• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.32 no.10
• /
• pp.12-19
• /
• 2004

An aerodynamic design optimization system for three-dimensional wing was developed as a part of the future MDO framework. The present design optimization system includes four modules such as geometry design, grid generation, flow solver and optimizer. All modules were based on commercial softwares and programmed to have automated execution capability in batch mode utilizing built-in script and journaling. The integration of all modules into the system was accomplished through programming using Visual Basic language. The distributed computational environment based on network communication was established to save computational time especially for time-consuming aerodynamic analyses. The distributed aerodynamic computations were performed in conjunction with the global optimization algorithm of response surface method, instead of using usual parallel computation based on domain decomposition. The application of the design system in the drag minimization problem demonstrated considerably enhanced efficiency of the design process while the final design showed reasonable results of reduced drag.

• 한국생물공학회:학술대회논문집
• /
• 2003.10a
• /
• pp.374-377
• /
• 2003

Hybridoma cells were adapted in media containing up to 80 mM $K^+$. The adapted cells obtained tolerance at high osmotic pressure and low pH. The adapted cells showed a maximum viable cell density of $1.1{\times}10^6$ cells/ml when a batch culture was progressed in a nutrient-fortified medium with Erlenmeyer flask at 450 $mOsm/kgH_2O,$ as compared to $4.8{\times}10^5$ cells/ml for non-adapted cells grown under the same conditions. The adapted cells also showed a maximum viable cell density of $7.8{\times}10^5$ cells/ml with the same method at initial pH 7.0 as compared to $5.3{\times}10^5$ cells/ml for non-adapted cells. Adaptation of animal cells at high $K^+$ levels may therefore lead to an improvement of their performance at limited conditions.

• Applied Chemistry for Engineering
• /
• v.26 no.2
• /
• pp.210-216
• /
• 2015

Adsorption of brilliant blue FCF dye using coal based the granular activated carbon from aqueous solution was investigated. Batch experiments were carried out as a function of the adsorbent dose, initial concentration, contact time and temperature. The equilibrium adsorption data were fitted to Langmuir, Freundlich and Temkin models. The results indicate that Freundlich model provides the best correlation of the experimental data. Base on the estimated Freundlich constant (1/n = 0.129~0.212), this process could be employed as an effective treatment method. Adsorption data were modeled using the pseudo-first-order and pseudo-second-order kinetic equations. It was shown that the pseudo-second-order kinetic equation could describe well the adsorption kinetics. The negative Gibbs free energy value (-4.81~-10.33 kJ/mol) and positive enthalpy value (+78.59 kJ/mol) indicated that the adsorption was a spontaneous and endothermic process.

• Applied Chemistry for Engineering
• /
• v.26 no.5
• /
• pp.581-586
• /
• 2015

Adsorption of Safranin using granular activated carbon from aqueous solution was investigated. Batch experiments were carried out as a function of adsorbent dose, initial concentration, contact time and temperature. The equilibrium adsorption data were fitted to Langmuir, Freundlich and Dubinin-Radushkevich isotherm models. Based on an estimated Langmuir separation factor, $R_L=0.183{\sim}0.254$ and a Freundlich separation factor, 1/n = 0.518~0.547, this process could be employed as an effective treatment method. Adsorption data were also modeled using the pseudo-first and second-order kinetic equations. It was shown that the pseudo-second-order kinetic equation could best describe the adsorption kinetics. The negative Gibbs free energy (${\Delta}G=-3.688{\sim}-7.220kJ/mol$) and positive enthalpy (${\Delta}H=33.126kJ/mol$) indicated that the adsorption process was spontaneous and endothermic.

• Journal of Fashion Business
• /
• v.14 no.3
• /
• pp.35-51
• /
• 2010

This study aims at providing data for establishing a marketing strategy which can enhance the competitiveness of Korea domestic SPA(Specialty Store Retailer of Private Label Apparel) Brands by suggesting countermeasure strategy through the observation and analysis for SPA Brands, under the current circumstance in which the systematic and scholastic discussion for the matter, is lack, despite the diastrophism in fashion industry is prospected according to the rapid growth of Global SPA Brands. For this purpose, the characteristic and current status of Global SPA Brands is examined, and the main cause of growth is analyzed by approaching to their marketing characteristic, in this study. In relation with this situation, this study suggests the provisions as below, which are drawn from the analysis on Global SPA Brands' marketing strategy, so that Korea domestic SPA Brands could achieve successive performance under fierce competition. First, to be a competitive SPA Brands a business should be able to supply products with frequent product turnover by an interval level of one week or so, the existent product planning by seasons, as a business obtains various swift informations on consumers' demand with R&D center foundation. Secondly, SPA Brands should establish a strategy that a business can create high net profit by inventory management which enables lowering inventory ratio remarkably, and a strategy for innovative product supply by small quantity batch production, along with founding a high technological logistics system. Third, SPA Brands should establish a strategy for primary cost reduction by overseas dispersed outsourcing in order to enable diverse product development and rational price setting. Fourth, fashion marketers should establish also a strategy for communication by which brand image can be delivered effectively, by firming the brand identity and by informing product characteristic and customer service totally, with the method of VMD and flagship store. Additionary, fashion marketers also should establish a strategy by developing mobile application which can provide brand image and diverse other fashion related information.

• The Korean Journal of Food And Nutrition
• /
• v.25 no.4
• /
• pp.850-854
• /
• 2012

This study is carried out in order to develop food materials for the promotion of rice consumption. In this study, we researched the physicochemical properties of extruded rice flour (ER) and gelatinization popped rice flour (GPR) by the extrusion process and by the popped method with milled rice and brown rice. The extrusion process used a couple of screw extruders. The extrusion parameter was kept constant at a feed moisture content of 25%, barrel temperature of $120^{\circ}C$ and screw speed of 400 rpm. GPR was prepared by batch popping machine after gelatinization of rice. In order to evaluate the physicochemical properties of ER and GPR, as well as the gelatinization rate, water soluble index (WSI), water adsorption index (WAI), DPPH radical scavenging activity and total dietary fiber content, the color value was carried out. The gelatinization rate was similar to 71.1~73.8%. Further, the results of WSI and WAI were increased at ER and GPR compared to the raw materials; ER was also higher than GPR. DPPH radical scavenging activity and total dietary fiber content showed a tendency to reduce after extrution and popping. As a result of the color value, the L value of ER decreased more than the raw materials, whereas GPR increased at a and b values.

• Journal of Korea Soil Environment Society
• /
• v.4 no.3
• /
• pp.85-93
• /
• 1999

The destruction of hazardous chemicals such as chlorinated organic compounds(COCs) and nitroaromatic compounds(NACs) by zero-valent iron powder is one of the latest innovative technologies. In this paper. the rapid dechlorination of chlorinated compounds as well as transformation of nitro functional group to amine functional group in the nitroaromatic compounds using synthesized zero-valent iron powder with nanoscale were studied in anaerobic batch system. Nanoscale iron, characterized by high surface area to mass ratios(31.4$\textrm{m}^2$/g) and high reactivity, could quickly reacts with compounds such as TCE, chloroform, nitrobenzene, nitrotoluene, dinitrobenzene and dinitrotoluene, at concentration of 10mg/L in aqueous solution at room temperature and pressure. In this study, the TCE was dechlorinated to ethane and chloroform to methane and nitro groups in NACs were transformed to amino groups in less than 30min. These results indicated that this chemical method using nanoscale iron powder has the high potential for the remediation of soils and groundwater contaminated with hazardous toxic chemicals including chlorinated organic compounds and nitro aromatic compounds.

• Journal of Soil and Groundwater Environment
• /
• v.19 no.5
• /
• pp.1-8
• /
• 2014

The metals contamination of farmland soil nearby abandoned metal mine was serious problem in Korea. Stabilization of contaminated soil was reported using various stabilizers. Application of limestone and steel refining slag was reported as effective stabilizers in the stabilization of metals. The batch studies confirmed that the mixture of limestone and steel refining slag was suitable for stabilization of metals in contaminated soil. The limestone and steel refining slag mixture (2 : 1 and 3 : 2) were used in column studies and it was confirmed that the stabilizers effectively stabilized heavy metals in contaminated soil. The pH of the soil was increased with the addition of stabilizers. Total leached concentration of metals from the column study was reduced 44, 17, and 93% in comparison to the control at arsenic, cadmium and copper, respectively. The sequential extraction studies showed that the exchangeable fraction was changed into carbonate bound fraction (Cd and Cu) and Fe-Mn oxide bound fraction (As). Based on the results we confirmed that 2:1 ratio of limestone and steel refining slag effectively stabilizes the heavy metals. The mixed treatment of lime stone with steel refining slag would be an effective and feasible method for controlling metals leaching in contaminated soil.

• Journal of the Korean Wood Science and Technology
• /
• v.44 no.6
• /
• pp.913-922
• /
• 2016

This study attempted to measure molecular weight (MW) of melamine-urea-formaldehyde (MUF) resins prepared by two different synthesis methods: the one-step MUF resins were synthesized in one batch procedure, while the two-step MUF resins were prepared by a physical mixing of urea-formaldehyde (UF) resin with melamine-formaldehyde (MF) resin that had been synthesized in a separate procedure. The properties of medium density fiberboard (MDF) panels bonded with two types of MUF resins were also investigated. MWs of these MUF resins were measured using gel permeation chromatography (GPC). In addition, this study measured the MWs of one-step MUF resin during its synthesis procedure. The performance of two types of MUF resins was evaluated by determining properties of MDF panels prepared in laboratory. As the synthesis procedure progressed, both number average MW ($M_n$) and weight average MW ($M_w$) of one-step MUF resin gradually increased, while the polydispersity index (PDI) decreased. And low Mw species of the resin predominantly decreased as the synthesis step progressed. The one-step MUF resin showed greater $M_n$ and $M_w$ than those of the two-step ones even though the PDI values of both resins were very similar each other. As expected, the one-step MUF resin resulted in better properties of MDF panels than those of two-step resins. In particular, the one-step MUF resin provided better internal bond (IB) strength and thickness swelling (TS) with MDF panels than those of two-step ones, indicating better water resistance of the one-step resin. These results suggest that the preparation method of MUF resins have a great impact on the MW and final panel properties.

• Polymer(Korea)
• /
• v.34 no.2
• /
• pp.144-149
• /
• 2010

Ag/polystyrene(PS) nanocomposites were prepared by in situ reduction of silver 2-ethylhexylcarbamate (Ag-CB) complex and follwing radical polymerization only by heating at 110 $^{\circ}C$. In contrast to this conventional heating method, the microwave irradiation afforded well-dispersed silver nanoparticles(NPs) in styrene monomer without polymerization. The synthesis of Ag NPs proceeded uniformly throughout the reaction vessel only under microwave irradiation, completing the reaction simultaneously in the whole reaction solution. Successive polymerization of the monomer containing the resultant NPs has successfully produced a hybrid of the silver NPs dispersed in PS matrix. Ag/PS (0.1/100) nanocomposites were prepared successfully by melt-mixing process using Ag/PS(4.0/100) as a master-batch. UV-VIS spectroscopy, TEM, and X-ray diffraction techniques were used to investigate the process of formation of Ag/PS nanocomposites.