• Journal of the Korean Society of Food Science and Nutrition
• /
• v.28 no.4
• /
• pp.890-894
• /
• 1999

Microencapsulation of anchovy oil as a core material in sodium alginate as a wall material was inves tigated. Microencapsulation was accomplished by injecting an oil/water emulsion, consisting of a mixture of liquefied sodium alginate and emulsifier, under high pressure through an orifice submerged in a calcium lactate solution. Microcapsules suspended in a dispersion fluid were observed under a fluorescence mi croscope to verify the presence of the capsules and to note coalescence or degradation of the capsules. Optimum conditions for microencapsulation of anchovy oil were obtained when 1.0% aqueous solution of sodium alginate contained 3% of a 1:1 ratio of ESPR 25(polyglycerine＋polylinoleate) and TW 20(sorbitan laurate＋ethylene oxide) as an emulsifier in terms of capsule size and size distribution, and emulsion stability. The airless sprayer produced microcapsules with a diameter between 15.9 and 73.9 m with different concentration of a wall material. The optimum mixing ratio of wall material to core material was 90:10(wt/wt). 0.2% calcium lactate was appropriate as a dispersion fluid.

• Journal of Electrical Engineering and Technology
• /
• v.7 no.6
• /
• pp.983-989
• /
• 2012

The purpose of this paper is to decide the optimum synthesis conditions of polycrystalline diamond films according to the ratio of gas mixture. Diamond films were deposited with cyclo-hexane as a carbon precursor by the microwave plasma enhanced chemical vapor deposition process. The optimum oxygen ratio to cyclo-hexane was reached about 125 % under the fixed 0.3% c-hexane in hydrogen. Oxygen plays a role in etching the graphitic components of carbon sp2 bond effectively. By OES measurement, the best synthesis conditions found out about 12.5 % and 15.75 %, which is the emission intensity ratios of CH(B-X) and $H{\beta}$ on $H{\alpha}$, respectively. Also, the electron temperature was similar about 5,000 to 5,200 K in this work.

• Journal of the Korean Society of Hazard Mitigation
• /
• v.11 no.3
• /
• pp.105-110
• /
• 2011

Recently, a deep mixture method as a soil improvement method of marine soft ground, which causes less noise and vibration than other methods, are widely used. In this study, for DCM(Deep Cement Mixing) method, one of the deep mixture method, optimum mixing ratio of clay-cement was suggested using uniaxial compression tests on specimens with various mixing ratio of claycement. In addition, the stability of a caisson on tangent circle-type and wall-type DCM treated ground was evaluated using centrifuge tests. As a result, optimum mixing ratio of clay-cement was 28.5% and the stability of the caisson on DCM treated ground was confirmed. However, the lateral displacement of the caisson on the wall-type DCM treated ground was 7% less and the settlement of that was 39% less than the case of the tangent-circle-type DCM method.

• International Journal of Highway Engineering
• /
• v.19 no.2
• /
• pp.137-142
• /
• 2017

PURPOSES :The objective of this study is to evaluate the performance of asphalt mixtures containing inorganic additive and a high content of reclaimed asphalt pavement (RAP). METHODS : The laboratory tests verified the superior laboratory performance of inorganic additive compared to cement, in cold recycled asphalt mixtures. To investigate the moisture susceptibility of the specimens, tensile strength ratio (TSR) tests were performed. In addition, dynamic modulus test was conducted to evaluate the performance of cold recycled asphalt mixture. RESULTS :It was determined that NaOH solution mixed with $Na_2SiO_3$ in the ratio 75:10 provides optimum performance. Compared to Type B and C counterparts, Type A mixtures consisting of an inorganic additive performed better in the Indirect tensile strength test, tensile strength ratio test, and dynamic modulus test. CONCLUSIONS : The use of inorganic additive enhances the indirect strength and dynamic modulus performance of the asphalt mixture. However, additional experiments are to be conducted to improve the reliability of the result with respect to the effect of inorganic additive.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.19 no.12
• /
• pp.3352-3359
• /
• 1995

An Eulerian-Lagrangian method is employed to simulate the ignition process and the flame propagation through the air/fuel spray mixture in a closed constant-volume combustor. The spray mixture is ignited by providing a hot wall at the end of the combustor or by firing the electric spark. The investigated parameters involve the initial droplet size, overall equivalence ratio, initial fuel vapor concentration, distance between the hot wall and the nearest droplet, and the ignition energy. Numerical results clearly show the existence of the optimum spray condition for minimizing the ignition energy and the ignition delay time as well as the critical dependence of ignition upon the distance of the heat source to the nearest droplet.

• Bulletin of the Korean Chemical Society
• /
• v.11 no.6
• /
• pp.527-530
• /
• 1990

The effects of the concentration and the pressure of reactants on laser output were reported in the previous study. The present study is made of the following main parameters on laser characteristics; the initial temperature of the reaction mixture, inert gas (He) added in the reaction mixture, and the level of initiation as a function of time. As the initial temperature of reaction mixture decreases, both the output energy and the duration time increase. Especially, the output energy is linearly proportional to the inverse of the initial temperature. In order to obtain a proper lasing for a given condition, a sufficient amount of He must be added: The optimum ratio of [He] to $[D_2\;+\;F_2\;+\;CO_2]$ is found to be greater than 2. In addition, the time dependence of level of initiation (TDLI) shows no significant difference in total output energy from that of the premixed model, but only the power profile.

• Korean journal of food and cookery science
• /
• v.22 no.6 s.96
• /
• pp.815-824
• /
• 2006

This study was performed to determine the optimum ratio of each ingredient in the steamed foam cake with barley (Hordeum vulgare L.) sproutling powder. The experiment was designed according to the D-optimal design of mixture design, which showed 14 experimental points including 4 replicates for three independent variables (sugar 112${\sim}$139%, barley sproutling powder 1${\sim}$8%, and oil 5${\sim}$25%). The compositional and functional properties of test were measured, and these values were applied to the mathematical models. A canonical form and trace plot showed the influence of each ingredient on the mixture final product. The results of F-test, volume, color values (L, a, b), textural properties (hardness, gumminess, chewiness) and sensory characteristics (softness) decided a linear model, while the sensory characteristics (color, smell, taste, overall acceptance) decided a quadratic model. The volume of steamed foam cake was increased by sugar addition, and a negative effect was exerted by barley sproutling powder and oil. L and a of color values increased but the b value decreased with increasing sugar and oil content, whereas barley sproutling powder tended to decrease all color values. The addition of barley sproutling powder also had a positive effect on the textural properties (hardness, gumminess, chewiness). Sensory characteristics (color, smell, softness, taste, overall acceptance) could suffer counter results with the excessive addition of sugar, barley sproutling powder, and oil. The optimum formulations by numerical and graphical methods were similar: sugar, barley sproutling powder, and oil were 130.4%, 4.0%, and 10.7% by numerical method, compared to 130.4%, 4.0%, and 10.7% by graphical method, respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.21 no.10
• /
• pp.923-929
• /
• 2008

On the piezoelectric polymer, PVDF (poly vinylidene fluoride), the transparent conducting oxide (TCO) electrode material thin film was deposited by roll to roll sputtering process mentioned as a mass product-friendly process for display application. The deposition method for ITO Indium Tin Oxides) as our TCO was DC magnetron sputtering optimized for polymer substrate with the low process temperature. As a result, a high transparent and good conductive ITO/PVDF film was prepared. During the process, especially, the gas mixture ratio of Ar and Oxygen was concluded as an important factor for determining the film's physical properties. There were the optimum ranges for process conditions of mixture gas ratio for ITO/PVDF From these results, the doping mechanism between the oxygen atom and the metal element, Indium or Tin was highly influenced by oxygen partial pressure condition during the deposition process at ambient temperature, which gives the conductivity to oxide electrode, as generally accepted. With our studies, the process windows of TCO for display and other application can be expected.

• Journal of Environmental Health Sciences
• /
• v.31 no.4 s.85
• /
• pp.294-300
• /
• 2005

Food waste can be a valuable carbon source in biological nutrient removal (BNR) systems because of high C/N and C/P ratios. However, food waste should be pretreated to promote its hydrolysis rate because hydrolysis reaction would be a rate-limiting step. This study investigates the influence of the enzymatic pretreatment on acid fermentation of food waste. Solubilization of particulate matter in food waste by using commercial enzymes was examined. The acidification efficiency and the volatile fatty acids (VFAs) production potential of enzymatically pretreated food waste were also examined. The highest volatile suspended solids (VSS) reduction was obtained with an enzyme mixture ratio of 1:2:1 of carbohydrase:protease:lipase. An optimum enzyme dosage for solubilization of food waste was $0.1\%$(V/V) with the enzyme mixture ratio of 1:2:1. In the acid fermentation of enzymatically pretreated food waste, $0.1\%$(V/V) enzyme mixture dosage for pretreatment result in the maximum VFAs production and the best VFAs fraction in soluble COD(SCOD). The VFAs production at this addition level was 3.3 times higher than that of no-enzyme added fermenter. The dominant VFAs present was n-butyrate followed by acetate.

• Food Science and Preservation
• /
• v.16 no.4
• /
• pp.472-481
• /
• 2009

Response surface methodology (RSM) is frequently used for optimization studies. In the present work, RSM was used to determine the antimicrobial activitiesof grapefruit seed extract (GFSE) and a lactic acid mixture (LA) against Staphylococcus aureus, Bacillus cereus, Escherichia coli, Salmonella typhimurium, Pseudomonas fluorescens, and Vibrio parahaemolyticus. A central composite design was used to investigate the effects of independent variables on dependent parameters. One set of antimicrobial preparations included mixtures of 1% (w/w) GFSE and 10% (w/w) LA, in which the relative proportions of component antimicrobials varied between 0 and 100%. In further experiments, the relative proportions were between 20% and 100%. Antimicrobial effects against various microorganisms were mathematically encoded for analysis. The codes are given in parentheses after the bacterial names, and were S. aureus ($Y_1$), B. cereus ($Y_2$), E. coli ($Y_3$), S. typhimurium ($Y_4$), P. fluorescens ($Y_5$), and V. parahaemolyticus ($Y_6$). The optimum antimicrobial activity of the 1% (w/w) GFSE:10% (w/w) LA mixture against each microorganism was obtained by superimposing contour plots ofantimicrobial activities on measures of response obtained under various conditions. The optimum rangesfor maximum antimicrobial activity of a mixture with a ratio of 1:10 (by weight) GFSE and LA were 35.73:64.27 and 56.58:43.42 (v/v), and the optimum mixture ratio was 51.70-100%. Under the tested conditions (a ratio of 1% [w/w] GFSE to 10% [w/w] LA of 40:60, and a concentration of 1% [w/w] GFSE and 10% [w/w] LA, 70% of the highest value tested), and within optimum antimicrobial activity ranges, the antimicrobial activities of the 1% (w/w) GFSE:10% (w/w) LA mixture against S. aureus ($Y_1$), B. cereus ($Y_2$), E. coli ($Y_3$), S. typhimurium ($Y_4$), P. fluorescens ($Y_5$), and V. parahaemolyticus ($Y_6$) were 24.55, 25.22, 20.20, 22.49, 23.89, and 28.04 mm, respectively. The predicted values at optimum conditions were similar to experimental values.