• Korean Chemical Engineering Research
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• v.54 no.1
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• pp.44-51
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• 2016

The powder core, conventionally fabricated from iron particles coated with insulator, showed large eddy current loss under high frequency, because of small specific resistance. To overcome the eddy current loss, the increase in the specific resistance of powder cores was needed. In this study, copper oxide coating onto electrically conductive iron particles was performed using a planetary ball mill to increase the specific resistance. Coating factors were optimized by the Response surface methodology. The independent variables were the CuO mass fraction, mill revolution number, coating time, ball size, ball mass and sample mass. The response variable was the specific resistance. The optimization of six factors by the fractional factorial design indicated that CuO mass fraction, mill revolution number, and coating time were the key factors. The levels of these three factors were selected by the three-factors full factorial design and steepest ascent method. The steepest ascent method was used to approach the optimum range for maximum specific resistance. The Box-Behnken design was finally used to analyze the response surfaces of the screened factors for further optimization. The results of the Box-Behnken design showed that the CuO mass fraction and mill revolution number were the main factors affecting the efficiency of coating process. As the CuO mass fraction increased, the specific resistance increased. In contrast, the specific resistance increased with decreasing mill revolution number. The process optimization results revealed a high agreement between the experimental and the predicted data ($Adj-R^2=0.944$). The optimized CuO mass fraction, mill revolution number, and coating time were 0.4, 200 rpm, and 15 min, respectively. The measured value of the specific resistance of the coated pellet under the optimized conditions of the maximum specific resistance was $530k{\Omega}{\cdot}cm$.

• Journal of Power System Engineering
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• v.19 no.2
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• pp.57-63
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• 2015

In this paper, we developed a continuous sterilizer in order to improve the productivity of the retort product. To this end, we design the sterilizer with a product inlet, outlet, and chain for continuously conveying the retort. The temperature analysis is performed to optimize the design parameters of the internal sterilizer. The experimental apparatus is developed to verify the productivity of the sterilizer based on the temperature analysis. The test is performed to optimize the evaluation parameters using Box-Behnken design method of a response surface methodology. From the test, the productivity of the continuous sterilizer is improved over 1,000 kg/h.

• Journal of the Korea Concrete Institute
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• v.21 no.6
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• pp.745-752
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• 2009

This paper presents the optimized mixing design of lightweight aerated concrete using hydrogen peroxide. Design of experiments in order to the optimized mixing design was applied and commercial program (MINITAB) was used. Statistical analysis was used to Box-Behnken (B-B) method in response surface analysis. The influencing factors of experimental are unit cement content, water ratio and hydrogen peroxide ratio. According to the analysis of variance, at the hardened state, water ratio and hydrogen peroxide ratio affects on dried density, compressive strength and bending strength of lightweight aerated concrete, but unit cement content affects on only dried density. In the results of response surface analysis, to obtain goal performance, the optimized mixing design for lightweight aerated concrete using hydrogen peroxide were unit cement content of 800 kg/$m^3$, water ratio of 44.33% and hydrogen peroxide ratio of 10%.

• Korean Chemical Engineering Research
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• v.51 no.6
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• pp.685-691
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• 2013

Ibuprofen, non-steroidal anti-inflammatory drugs; NSAIDs, is a highly crystalline substance with the pharmaceutical properties of poor solubility and low bioavailability. The size reduction of ibuprofen is needed to improve the solubility. The objective of this study is to optimize the grinding condition of ibuprofen. Grinding of ibuprofen was carried out using a planetary mill. Grinding parameters were optimized using Box-Behnken experimental design method. The physical characteristics of ground ibuprofen were investigated for the particle size by particle size analyzer, for the crystal size by X-ray diffraction (XRD), and for the tensile strength by tensile/compression tester. The optimum conditions for the milling of ibuprofen were 290 rpm of the revolution number of mill, 24.6 g of the weight of sample, and 10 minutes of grinding time. The measured value of the particle size of ground ibuprofen at these optimum conditions was $13.5{\mu}m$. The results showed that the crystal size of ibuprofen was reduced by the planetary milling process. In case the relative density of the tablets formulated of ground ibuprofen was range of 0.85~0.90, the tensile strength of them was range of 1$2{\sim}14Kg_f/cm^2$.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.12 no.1
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• pp.63-69
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• 2013

Many researchers are trying to reduce the use of lubrication fluids in metal cutting to obtain safety, environmental and economical benefits. The aim of this study is to determine the optimization lubrication conditions in minimum quantity lubrication(MQL) turning of workpieces with taper angle. This study has been considered about various conditions of MQL. The objective functions are cutting force and surface roughness. Design factors are nozzle diameter, nozzle angle, MQL supply pressure, distance between tool and nozzle and length of supply line. The cutting force and surface roughness were statistically analyzed by the use of the Box-Behnken method. As a results, optimum lubrication conditions were suggested and verification experiment has been performed. The results of this study are expected to help the selection of lubrication conditions in MQL turning.

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.313-319
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• 2007

The nutritional medium requirement for biosurfactant production by Bacillus licheniformis K51 was optimized. The important medium components, identified by the initial screening method of Plackett-Burman, were $H_3PO_4,\;CaCl_2,H_3BO_3$, and Na-EDTA. Box-Behnken response surface methodology was applied to further optimize biosurfactant production. The optimal concentrations for higher production of biosurfactants were (g/l): glucose, $1.1;NaNO_3,\;4.4;MgSO_4{\cdot}7H_2O,\;0.8;KCl,\;0.4;CaCl_2,\;0.27;H_3PO_4,\;1.0ml/l;\;and\;trace elements\;(mg/l):H_3BO_3,\;0.25;CuSO_4,\;0.6;MnSO_4,\;2.2;Na_{2}MoO_4,\;0.5;ZnSO_4,\;6.0;FeSO_4,\;8.0;CoCL_2,\;1.0;$ and Na-EDTA, 30.0. Using this statistical optimization method, the relative biosurfactant yield as critical micelle dilution (CMD) was increased from $10{\times}\;to\;105{\times}$, which is ten times higher than the non-optimized rich medium.

• International Journal of Highway Engineering
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• v.15 no.6
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• pp.69-78
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• 2013

PURPOSES : In this study blast furnace slag, an industrial byproduct, was used with an activating chemicals, $Ca(OH)_2$ and $Na_2SiO_3$ for carbon capture and sequestration as well as strength development. METHODS : This paper presents the optimized mixing design of Carbon-Capturing and Sequestering Activated Blast-Furnace Slag Mortar. Design of experiments in order to the optimized mixing design was applied and commercial program (MINITAB) was used. Statistical analysis was used to Box-Behnken (B-B) method in response surface analysis. RESULTS : The influencing factors of experimental are water ratio, Chemical admixture ratio and Curing temperature. In the results of response surface analysis, to obtain goal performance, the optimized mixing design for Carbon-Capturing and Sequestering Activated Blast-Furnace Slag Mortar were water ratio 40%, Chemical admixture ratio 58.78% and Curing temperature of $60^{\circ}C$. CONCLUSIONS : Compared with previous studies of this experiment is to some extent the optimal combination is expected to be reliable.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.9
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• pp.917-925
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• 2006

The aim of our research was to apply experimental design methodology in the optimization of photocatalytic degradation of azo dye(Reactive orange 16). The reactions were mathematically described as a function of parameters amount of $TiO_2(x_1)$, and dye concentration($x_2$) being modeled by the use of the Box-Behnken method. The results show that the responses of color removal(%)($Y_1$) in photocatalysis of dyes were significantly affected by the synergistic effect of linear term of $TiO_2(x_1)$ and dye concentration($x_2$). Significant factors and synergistic effects for the $COD_{Cr}$, removal(%)($Y_2$) were the linear term of $TiO_2(x_1)$ and dye concentration($x_2$). However, the quadratic term of $TiO_2(x_1^2)$ and dye concentration($x_2^2$) had an antagonistic effect on $Y_1$ and $Y_2$ responses. Canonical analysis indicates that the stationary point was a saddle point for $Y_1$ and $Y_2$, respectively. The estimated ridge of maximum responses and optimal conditions for $Y_1:(X_1,\;X_2)$=(1.11 g/L, 51.2 mg/L) and $Y_2:(X_1,\;X_2)$=(1.42 g/L, 72.83 mg/L) using canonical analysis was 93% and 73%, respectively.

• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.435-440
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• 2018

Nyamplung (Calophyllum inophyllum Linn) is one of the most widely grown plants in Indonesia. In addition, nyamplung oil has a future competitive advantage in that it can be processed into biodiesel. However, conventional methods for transesterification of nyamplung oil have been less effective. Therefore, in this study biodiesel was produced using microwaves as one of the alternative methods that can improve the shortcomings of conventional methods. In addition, optimization of parameters such as microwave power, catalyst concentration and transesterification time was done using Box-Behnken design. The combination of microwave with CaO catalyst and treated with Box-Behnken design are considered as a new and modern method for production of biodiesel from nyamplung oil and optimizing the factors that affected the transesterification process. The results showed that factors such as microwave power of 449.29 W, concentration of catalyst of 4.86% and transesterification time of 10.07 min can produce optimal yield of biodiesel of 92.73% with reliability of 93.22%.

• Environmental Engineering Research
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• v.23 no.2
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• pp.175-180
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• 2018

Box-Behnken Design (BBD) under response surface methodology (RSM) was implemented to optimization the operating parameters and assess the removal and recovery efficiencies of crude oil from contaminated soil using subcritical water extraction. The effects of temperature, extraction time and water flow rate were explored, and the results indicate that temperature has a great impact on crude oil removal and recovery. The correlation coefficients for oil removal ($R^2=0.74$) and recovery ($R^2=0.98$) suggest that the proposed quadratic model is useful. When setting the target removal and recovery (>99%), BBD-RSM determined the optimum condition to be a temperature of $250^{\circ}C$, extraction time of 120 min, and water flow rate of 1 mL/min. An experiment was carried out to confirm the results, with removal and recovery efficiencies of 99.69% and 87.33%, respectively. This result indicates that BBD is a suitable method to optimize the process variables for crude oil removal and recovery from contaminated soil.