• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.427-430
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• 2003

The Mixers is used for the Mixing which is the most important process in the Water&Sewage water treatment. To choose proper mixer required much career and knowledge, to check many elements which are purpose, time and condition of mixing. Thus, the design method of mixers is to be utilized for the structural design of the water & Sewage water treatment.

• Journal of Biosystems Engineering
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• v.33 no.2
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• pp.130-135
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• 2008

The purpose of this study was to develop a preprocessor for real-time portable quality evaluation system of milk. The preprocessor consisted of two flow pump to supply milk sample and reaction reagent at given volume, a fan to mix milk with reaction reagent, a thermoelectric device to maintain sample temperatures of $40^{\circ}C$, and I/O interface to control signals. The tests conducted with different level of flow rate of pump, fan speed, ambient temperature, and intial temperature of mixtures. To evaluate performance of the preprocessor, the supplied volumes, color changes, and temperatures were measured and analyzed. The results showed that the preprocessor could control supplying volumes, mixing, temperatures of samples automatically. The preprocessor showed good performance to be used for portable quality evaluation system of milk.

• Archives of Pharmacal Research
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• v.27 no.8
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• pp.873-877
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• 2004

This study was designed to determine the optimum conditions of three different factors (mixing time, mixing temperature, and tube size) in reduction of cholesterol in milk using immobilized $\beta$-CD beads. Immobilized $\beta$-CD glass beads were prepared at different conditions of silaniza-tion and $\beta$-CD immobilization reactions. In result, the glass beads (diameter 1 mm) at 20 mM 3-isocyanatopropyltriethoxysilane and 30 mM $\beta$-CD without base showed the highest choles-terol removal rate as 41%. Using above immobilized $\beta$-CD glass beads, the cholesterol removal rate was 40.2% with 6 h of mixing time in 7 mm diameter tube at $10^{\circ}C$. After choles-terol removal from milk, the glass beads were washed for cholesterol dissociation and reused. In recycling study, the cholesterol removal rate was 41%, which was mostly same as that using new glass beads. These results indicated that cholesterol removal rate was about 40% with $\beta$-CD immobilized glass beads, however, the recycling efficiency was almost 100%.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.1
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• pp.108-115
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• 2019

The thermal response of elastomeric insulators used as protection against high-temperature and high-pressure combustion gases varies depending on their composition and thermal environment conditions. In this paper, the thermal response characteristics of elastomeric insulators in different mixing environments were compared. Tests to determine thermal protection performance were carried out using a thermal protection rubber evaluation motor(TPREM), combustion gas velocities of 20 m/s and 100 m/s were tested at a chamber pressure of 1,000 psig. The pressure time curve of the chamber, the temperature time curve of the internal materials, the residual thickness and the thermal destruction depth of the test specimens were obtained. The results showed that the thermal protection performance of elastomeric insulators in different mixing environments was similar.

• Journal of the Korean Geotechnical Society
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• v.34 no.10
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• pp.39-49
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• 2018

In this study, aimed at determining the elastic modulus of deep mixed samples, 320 test specimens were developed by mixing 8%, 10%, 12%, and 14% of stabilizer mixture in the granular conditions of clay, sand and gravel. Uniaxial compression tests were carried out using these specimens, and the uniaxial compression strength and strain were analyzed to determine the secant elastic modulus and tangent elastic modulus. Laboratory test results showed that the uniaxial compression strength of all deep mixed samples increased with increasing curing time and stabilizer mixing ratio, and that the secant elastic modulus and the tangen elastic modulus also increased. The increase of the elastic modulus according to the curing period turned out greater in the tangent elastic modulus than in the secant elastic modulus. In order to measure elastic modulus with changes in stabilizer mixing ratio, the correlation coefficient between the elastic modulus for stabilizer mixing ratio of 8% and that of 10%, 12% and 14% was calculated respectively by the specimen condition. The elastic modulus tended to increase as the grain size in a deep mixed specimen increased. The distribution of grain size that had the greatest effect appeared when the composition ratio of sand was high. On the other hand, the increase in the elastic modulus was larger in the sand specimens than in the clay and gravel specimens. Based on these results, it is suggested that a pertinent soil parameter of the deep mixed ground in the field may be obtained by the particle size distribution and the mixing ratio of stabilizer of the deep mixed soil.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.197-198
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• 2023

This study was conducted as part of research and development of high-strength grout. Accordingly, dolomite aggregate was used as a filler incorporated into the high-strength grout. Dolomite aggregate has a disadvantage of increasing the viscosity of the grout due to higher generation of fine powder than other aggregates. Accordingly, in this experiment, it was confirmed that the viscosity, flow time, and flow of high-strength grout change according to the volume composition ratio of dolomite aggregate and cement-based material. All experiments were conducted based on the Korean Industrial Standard KS F 4044, and the mixing factor was applied according to the composition ratio of the binder and the filler. In the experiment, the amount of fine powder contained in the dolomite aggregate rather than the silica sand used in the past is grasped, and after mixing with the grout accordingly, the mixture is proceeded to measure the viscosity in an unhardened state. In addition, the flow and flow time of the grout are evaluated according to the viscosity. As a result of the experiment, it was confirmed that the viscosity and flow time decreased and the flow increased as the volume composition ratio of the dolomite aggregate to the cement-based material increased.

• KSBB Journal
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• v.7 no.1
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• pp.59-65
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• 1992

Hydrodynamics and mixing characteristics such as circulation time, mixing time, circulation velocity and axial dispersion coefficient were investigated using highly viscous pseudoplastic solutions of carboxymethyl cellulose(CMC) in an external circulation loop air-lift reactor with 13$\ell$ working volume. The superficial gas velocity was changed from 1.9 to 6.2cm/s and CMC concentration from 0 to 1.0wt%. The theoretical model based on the pressure balance is developed mathematically to predict liquid circulation velocity. Gas hold-up, circulation velocity and axial dispersion coefficient of liquid phase increased with increasing gas velocity and decreased slightly with increasing liquid viscosity. Mixing time and circulation time decreased with increasing gas velocity and increased with increasing liquid viscosity. Experimental data on liquid circulation velocity were in good agreement with the predicted values.

• Journal of the Korean GEO-environmental Society
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• v.22 no.12
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• pp.59-63
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• 2021

This study presented the characteristics and additive effects of the grout with mixing ratio for developing of high-efficiency grouting technology under high depth conditions. The laboratory investigation were conducted with Portland cement (OPC) and micro cement (S8000-E) including viscosity experiments, particle size analysis experiments, Gel-Time experiments and uniaxial compressive strength experiments. As a result of the viscosity experiment, it was shown that OPC is advantageous in terms of viscosity, but S8000-E is suitable when considering the passage of rock joint intervals through particle size analysis. The Gel-Time experiment shows that it is not that difficult with injection as a grout material even when silica fume (SF) was applied. The strength of the cured material is improved as increase in the content of silica fium (SF). Within the range of the study, the optimal mixing ratio obtained through various experiments is S8000-E, w/c=70%, silica fium (SF)=6%, and 7 days.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.767-772
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• 2003

The clay which transported into a pond under the high water content condition have no effective stress which develop from the starting point of sedimentation and self-weight consolidation. Since sedimentation and self-weight consolidation dependent on self-weight of solids is made progress over a long time, to accelerating it have many advantages in the economic view In this paper, sand spreading method which is one of sedimentation and self-weight consolidation acceleration method is studied through a series of experiments considering the mixing ratio of sand and clay. The test results show that the mixing ratio of clay and sand of 1:0.2 is the biggest rate of consolidation and the pouring at the end point of sedimentation considerably effects on consolidation rate.

• Journal of computational fluids engineering
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• v.15 no.1
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• pp.9-16
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• 2010

The characteristics of flow and heat transfer in a bubbling fluidized bed are investigated by means of computational fluid dynamics (CFD). To simulate two-phase flow for the gas and solid flows, Eulerian-Eulerian approach is applied. Attention is paid for a heat transfer from the wall to fluidized bed by bubbling motion of the flow. From the result, it is confirmed that heat transfer is promoted by chaotic bubbling motion of the flow by enhancement of mixing among solid particles. In particular, the vortical flow motion around gas bubble plays an important role for the mixing and consequent heat transfer. Discussion is made for the time and space averaged Nusselt number which shows peculiar characteristics corresponding to different flow regimes.