• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.159-160
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• 2022

The purpose of this study is to evaluate the adhesion in flexure depending on the cement type, polymer type, polymer-cement ratio, and silica fume ratio of the polymer-cement composites(PCCs) for crack repair in RC structures to induce optimal mix proportions. The adhesion in flexure of PCCs for crack repair of RC structure has a significant effect on the polymer type and polymer-cement ratio, and the adhesion in flexure is generally improved with mixing of silica fume as a mixture. The adhesion in flexure according to the type of polymer is slightly higher in the order of SAE, EVA, and SBR, and it is relatively high at the polymer-cement ratio of 60% or 80%. In addition, the adhesion in flexure of PCCs with silica fume ratio of 10% or 20% to the cement weight is higher than that without silica fume. In order to improve the adhesion in flexure of PCCs for repairing cracks in RC structures, the optimal mix design is to properly adjust the cement type, polymer type, polymer-cement ratio, and silica fume ratio.

• Korean journal of food and cookery science
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• v.28 no.1
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• pp.67-76
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• 2012

This study examined the optimal ingredient mixing ratio for the preparation of steamed cake containing mugwort (Artemisia princeps var. orientalis) powder. After preliminary studies, the following ingredient ranges were determined; 110~129% sugar, 3~8% mugwort powder, 10~25% oil. Among the different mixture designs, the D-optimal design was chosen for analysis. The results of F-test, specific gravity, viscosity, volume and color values (L, a, b), hardness decided a linear model, while the sensory characteristics (color, taste, texture and overall acceptance) decided a quadratic model. The fitness analysis results showed that in all characteristic, the probabilities were significant within 0.05%; thus, the models were accepted as appropriate. The response surface and trace plot results showed that increasing amounts of mugwort powder decreased the brightness, and increased redness and yellowness. As the level of added oil increased, the softness of the cake increased. Cake samples received low sensory evaluation scores when sugar, mugwort powder, and oil were added above their optimal levels. The optimum formulations by the numerical and graphical methods, were similar, and with the numerical method presented as: sugar, mugwort powder, and oil at 120.7%, 5.1%, and 16.2%, respectively(flour weight basis). The above results demonstrate the feasibility of adding mugwort powder to sponge cake, and therefore, the commercialization of mugwort powder cake marketed as a functional food is deemed possible.

• Journal of computational fluids engineering
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• v.7 no.2
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• pp.1-7
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• 2002

The present study is developed device that effectively mixes raw water and chemicals by using the residual head of fluid in the front pipe of flocculation basin, and performed non-dimensional analysis and presented design standard to apply to water plants that have different equipment capacity. The variables for design are a proper ratio between an outer diameter of deflector and a diameter of pipe, a distance between deflector and orifice and a determination of orifice diameter for an optimal mixing. Numerical study has analyzed flow field on a basis of turbulent intensity in an orifice downstream. As Reynolds number of In-Line Orifice was increased from identical design variable, the turbulent intensity of pipe center was no changed almost.

• Korean journal of food and cookery science
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• v.22 no.2 s.92
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• pp.164-172
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• 2006

The purpose of this study was to find the optimal mixing condition of three different amounts of pine leaf powder, butter and sugar for preparation of pine leaf cookies. The optimum mixing condition for pine leaf cookies was optimized by response surface methodology The optimum mixing rates of pine leaf powder, butter and sugar were 8.6 g, 252.8 g and 154.1 g for color, 8.4 g, 240.7 g and 149.8 g for appearance, 8.8 g, 246.5 g and 154.7 g for flavor and 10.9 g, 277.1 g and 134.6 g for texture respectively. The optimum mixture ratio which fulfilled all items was pine leaf powder 9.4 g, butter 270.5 g and sugar 141 g.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.179-180
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• 2023

The adhesion performance of PCCs for crack repair of RC structures was greater in the case of using ultra high-early strength cement than in the case of using ordinary Portland cement, and the effect of mixing silica fume was higher in the case of ordinary Portland cement than that of ultra high-early strength cement. On the other hand, 130% of W/C was more fluid than 80% of W/C in the same P/C 80%, which increased the fillability and improved the strength, but the strength improvement effect was the greatest in adhesion in flexure. Through this study, the basic characteristics of the adhesion performance of PCCs were identified, and based on this, it is necessary to induce an optimal mixing design that can increase adhesion performance through various mixing designs.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.3
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• pp.273-278
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• 2007

Modern society has moved from a phosphorus recycling loop, where animal manure and human wastes were spread on farming land to recycle nutrients, to a once-through system, where phosphates are extracted from mined, non-renewable phosphate rock and end up either in landfill(sewage sludge, incinerator ash) or in surface waters. In this research, crystallization of nitrogen and phosphate with natural sources of $Mg^{2+}$ in synthetic water was tested. The operational parameters of pH, mixing time, and the magnesium molar ratio were investigated to find optimal conditions of the MAP precipitation using synthetic wastewater. The removal efficiency of phosphate increased with pH up to 11. By MAP precipitaiton of the synthetic waste water, 94% of the phosphate were eliminated at pH 11. It was found that at least 10 minutes mixing time was required and 20 minutes mixing time was recommended for efficient phosphate removal. High efficiency removal of phosphate was possible when the magnesium molar ratio was 1.0~2.0. The comparative study of different magnesium sources showed that coagulants (PAC) was the more efficient sources than only magnesium. The result showed that 97% of phosphate removal. In conclusion, coagulants (PAC) induced crystallization of struvite and hydroxyapatite was shown to be a technically viable process that could prove cost effective for removing phosphate in wastewater.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.21 no.2
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• pp.112-128
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• 1995

This study was undertaken to see the effect of the addition of residential sewage to cosmetic plant wastewater on the aeration time for COD stabilization of the mixture in a bioreactor. Various range of mixing-ratio samples were tested to find the optimal mixing ratio. The combined result of measured COD and the minimum aeration time was desirable when the sewage portion was 80%. It was found that the addition of residential sewage to cosmetic plant wastewater itself reduced the measured COD of the mixture without any further treatment. And during the aeration COD was reduced with increasing the portion of the sewage. These results show that the aeration time for COD stabilization can be reduced by pro-mixing of residential sewage and the cosmetic plant wastewater.

• Korea-Australia Rheology Journal
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• v.17 no.4
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• pp.165-170
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• 2005

In this study, high intensity ultrasound was employed to induce mechano-chemical degradation during melt mixing of polycarbonate (PC) and a series of styrene-acrylonitrile (SAN) copolymers. It was confirmed that generation of macroradicals of constituent polymers can lead to in-situ copolymer formation by their mutual combination, which should be an efficient path to compatibilize immiscible polymer blends and stabilize their phase morphology in the absence of other chemical agents. Based on the effectiveness of the compatibilization by ultrasound assisted mixing process, we investigated the effects of viscosity ratio of PC and SAN and AN content in SAN on the compatibilization of PC/SAN blends. It was found that effectiveness of compatibilization is optimal when the AN content is in the range of favorable interaction with PC and the viscosity of the matrix is higher than that of the dispersed phase. In addition, changes in the interfacial tension between PC and SAN were assessed by examining relaxation spectra which were obtained from measuring rheological properties of ultrasonically treated blends.

• Food Science and Preservation
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• v.9 no.2
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• pp.189-193
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• 2002

This study was conducted to evaluate the quality and the quantity for manufacturing vinegar powder using spray drying. The $\beta$-cyclodextrin(CD) and gum arabic(GA) were used as well materials and the mixing ratio of CD and GA was ranged from 10:0 to 0:10. The moisture content of the vinegar powder of 2.5 of CD and 7.5 of GA was lowest among the other mixing ratios. At this proportion, the titratable acidity was highest as it had much included vinegar. The heat stability was not varied much with mixing ratio. However the stability of heat was maintained. Further the water absorption of powder was comparatively low. The manufactured powder vinegar shape was smooth round particles and stable structure by SEM and the particle size was small enough to form capsulation. In sensory evaluation, under these conditions the sourness was highest at 3.5. Therefore, the optimal mixing ratio at 2.5 of CD and 7.5 of GA in wall material was selected.

• Clean Technology
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• v.29 no.2
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• pp.102-108
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• 2023

This study applied a hydrothermal carbonization (HTC) method to carbonize sewage sludge in order to satisfy the criteria of the Waste Management Act for recycled products and to explore the possibility of recycling sludge into modification blocks. Cement was mixed with carbonized sludge generated at the optimal temperature and reaction time during HTC. After that, the compressive strengths of the modification blocks were measured by conducting both a performance and leaching test. The results of the leaching test showed that heavy metals were not detected, and the specific gravity and absorption rates were less than 1.7 and 10%, respectively, indicating that all species satisfied the criteria. The results of the compressive strength test showed that a mixing ratio of 5% and 7% with cement cured for 28 days satisfied the criteria of A, B, and C type blocks but a mixing ratio of 3% with cement did not satisfy the criteria of A type blocks after 28 days. However, after additional curing for 42 days, the mixing ratio of 3% also satisfied the A type block criteria. Therefore, the optimal mixing ratio of carbonized sludge and cement was considered to be between 3% and 5% and confirmed that the modified blocks could be utilized as aggregates.