• The KSFM Journal of Fluid Machinery
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• v.5 no.2 s.15
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• pp.15-21
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• 2002

The hydraulic performance analysis of an entire pump system composed of inducer, impeller, volute and seal for the application of turbopumps is numerically performed using three-dimensional Navier-Stokes equations. A quasi-steady mixing-plane method is used on the impeller/volute interface to simulate the unsteady interaction phenomena. From this work, the effects of each component on the pump performance are investigated at design and off-design conditions through the analysis of flow structures and loss mechanisms. The computational results are in a good agreement with experimental ones in terms of the headrise and efficiency even though very complex flow structures are present. It is found that the asymmetric pressure distribution along the volute wall constitutes the main reason of the difference between experimental and computational results, due to the limitation of the quasi-steady method. Since the volute was found to be over-designed by the pressure distribution of the volute wall, re-design of the volute has been performed, resulting in an improved performance characteristic.

• Journal of Pharmaceutical Investigation
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• v.40 no.6
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• pp.321-332
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• 2010

Growing interest in the nasal route as a drug delivery system calls for a reliable in vitro model which is crucial for efficiently evaluating drug transport through the nasal cells. Various in vitro cell culture systems has thus been developed to displace the ex vivo excised nasal tissue and in vivo animal models. Due to species difference, results from animal studies are not sufficient for estimating the drug absorption kinetics in humans. However, the difficulty in obtaining reliable human tissue source limits the use of primary culture of human nasal epithelial cells. This shortage of human nasal tissue has therefore prompted studies on the "passage" culture of nasal epithelial cells. A serially passaged primary human nasal epithelial cell monolayer system developed by the air-liquid interface (ALI) culture is known to promote the differentiation of cilia and mucin gene and maintain high TEER values. Recent studies on the in vitro nasal cell culture systems for drug transport studies are reviewed in this article.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1738-1743
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• 2004

Turbo-pump system, an essential component of liquid rockets and induced weapons, adopts a partial admission axial turbine which drives pump. And the turbine of a turbo-pump system is usually operated at supersonic condition due to its high loading chracteristics. Therefore, reseaches about flow and performance characteristics of a partial admission supersonic turbine must be preceeded to progress the aerospace and defense industries as well as the development of turbo-pump systems. In this study, flow characterisitics within blades of the partial admission supersonic turbine are numerically investigated by using Fine Turbo, a commercial CFD Code. Before performing the numercial analyses, to verify accuracy of the numerical result computed by Fine Turbo, I performed the comparison between the numerical results with J.J.Cho' experimental results. It is found that the numerical results show good agreement with the experimental results. Computations about the partial admission supersonic turbine have been performed to investigate flow characteristics including shock patterns. It is also found that the flow and performance of partial admission supersonic turbine are largely depend on shocks ocurred in the nozzle and at the leading edge of blades, expansion or compression at exit of nozzle and separations occurred in passage.

• Journal of the Korean Applied Science and Technology
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• v.27 no.3
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• pp.266-272
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• 2010

Natural Ginger extract was extracted from Ginger component using ethanol as a solvent, and we tested various pharmaceutical characteristics in this extract. Characteristics experiment to use natural Ginger extract tested antimicrobial experiment using microbe, and analyzed organic and inorganic component with analysis instrument. From the result of characteristics experiment, some conclusions are obtained as follow. In this experiment, natural Ginger extract was obtained about 22.50 g-Ginger extract(extraction ratio : 1.80%) as liquid state of some viscous yellow-brown color. The result of antimicrobial experiment with staphylococcus aureus and aspergillus niger in microbe decreased more and more according to passage of reaction time. This phenomenon could know that Ginger extract has influenced to antimicrobial effect. In the result of instrumental analysis, aromatic organic components of benzimidazole(1.283), propyl isothiocyanate or isothiocyanic acid(1.477) etcs from Ginger extract were detected with GC/MS and inorganic component of Ca(27.6 ppm), K(24.08 ppm), Mg(6.03 ppm), Na(1.02 ppm), Zn(1.02 ppm), Sb(0.711 ppm) and Li(0.079 ppm) etcs from Ginger extract were detected with ICP/OES.

• Journal of the Society of Naval Architects of Korea
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• v.56 no.3
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• pp.187-199
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• 2019

In the case of gas carriers and oil tankers, pipes are installed on the upper deck as a moving passage to load LPG, LNG, crude oil, etc. Pipes used for loading or unloading liquid cargo in cargo holds are connected to the hull through support structures. However, many cases of hull damage have been reported where the various equipment and support structures are installed on the upper deck. It is assumed that not only the structural discontinuity where the hull and the pipe support structure meet, but also action due to the pipe loads and the hull girder bending moment are simultaneously affected. This paper deals with the design and strength evaluation of the support structure of pipes and cables installed on the upper deck of commercial ships and offshore structures. For these supporting structures, design conditions and working loads were defined. The design procedure was established through the structure analysis on the method of determining the member dimensions. A series of finite element analysis was performed on the factors to be considered in the design and the effects were discussed. The accuracy and design periods of the strength evaluation was improved and reduced by application of the automation program in the finite element analysis. It is also expected that the design reliability of the shipyard is improved.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.22 no.2
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• pp.182-192
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• 1996

In this study, the relationship between wax matrix in lipstick and sweating was investigated by observing the change of size and shape of wax matrix with sweating by Scanning Electron Microscopy (SEM). For observation by SEM, a lipstick sample was frozen in liquid nitrogen, then the oil in the lipstick was extracted out in cold isopropanol($-70^{\circ}C$) for 1-3days. After isopropanol was evaporated, the sample was sputtered with gold, and examined by SEM. When examined the sweated sample by SEM, the change of wax matrix underneath the surface from fine, uniform structure to coarse, nonuniform structure was observed, which was resulted from the caking of surrounding wax matrix. That is, the oil underneath the surface was migrated to the surface of lipstick with sweating, consequently the wax matrix at that region was rearranged into the coarse matrix. In case of flamed lipstick, sweating was delayed and the wax matrix was much coarser than that of unflamed one. Its larger wax matrix at surface region was good for including oil. The effect of molding temperature on sweating was also studied. As the molding temperature was increased, sweating was greatly reduced and the size of wax matrix was increased. It was also found that sweating was influenced with the compatinility of wax and oil. A formula consisting of wax and oil which have good compatibility has a tendency of reduced sweating and increased size of wax matrix. When pigment was added to wax and oil. It was also found that sweating was influenced with the passage of time by observing a thick membrane of wax on surface of lipstick after a month from molding. In case of some lipsticks, the size of wax matrix was altered to bigger or smaller. In conclusion, the structure of wax matrix at the surface region of lipstick was changed with the process of foaming, molding temperature, compatibility of wax and oil, addition of pigment, and the passage of time. In most cases, as the size of wax matrix was increased, sweating was reduced and delayed.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5409-5413
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• 2012

At present, multiple myeloma (MM) remains an incurable disease and cologenic cells may be responsible for disease relapse. It has been proposed that CD20+/CD138- NCI-H929 cells could be hallmarks of MM clonogenic cells. Here, the immunology phenotype of NCI-H929 cells is described. Only a small population of CD20+/CD138- cells (<1%) was found in the NCI-H929 cell line, but CD20+/CD138- cells were not detected. We found that CD20+/CD138+ cells were able to exhibit cologenic capacity by colony formation assay and continuous passage culture. Proteins were analyzed by 1D-SDS-PAGE and TMT based quantitative differential liquid chromatography tandem mass spectrometry (LC-MS/MS). 1,082 non-redundant proteins were identified, 658 of which were differentially expressed with at least a 1.5-fold difference. 205 proteins in CD20+ cells were expressed at higher levels and 453 proteins were at lower levels compared with CD20- cells. Most proteins had catalytic and binding activity and mainly participated in metabolic processes, cell communication and molecular transport. These results proved that there are different biological features and protein expression profile between CD20+ and CD20- cells in the NCI-H929 cell line.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.731-736
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• 2011

A pneumatic driving solenoid valve operates pneumatic control devices by opening/closing operating flow passage when the command is given by control system for the liquid-propellant feeding system of space launch vehicle. The simulation model of pneumatic driving solenoid valve is designed with AMESim to verify the designs and evaluate the dynamic characteristics and pneumatic behaviors of valve. To validate a valve simulation model, the simulation results of their operating durations of valve by AMESim analysis are compared with the results of experiments. In addition, the results of internal flow simulation with FLUENT are utilized to improve the accuracy of valve-modeling. Using the model, we analyze performance of valve; opening/closing pressure, operating time on various design factors; shape of control valve seat, drainage seat, rate of sealing diameter, volume of control cavity. This study will serve as one of reference guides to enhance the developmental efficiency of ventilation-relief valves with the various operating conditions, which shall be used in Korea Space Launch Vehicle-II.

• Applied Biological Chemistry
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• v.25 no.4
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• pp.197-200
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• 1982

Pasteurization conditions of chinese cabbage-Kimchi were investigated in the Kimchi pasteurizer which sterilized the liquid portion and mixed with that of non-heat treated solid of Kimchi in a constant volume reservoir. The shelf-life of the sterilized Kimchi were compared at various temperature 75, 81, $85^{\circ}C$ and pasteurization cycles - numbers of passage through holding section of the pasteurizer-for the optimum pasteurization conditions. The optimum temperature were $75^{\circ}C$ for one cycle and $81^{\circ}C$ for 3 cycles. More than two weeks shelf-life of Kimchi was prolonged when pasteurized 3 cycles at $81^{\circ}C$. Similar results were obtained with the seasoned Kimchi containing red pepper powder.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.11
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• pp.1559-1569
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• 2002

In order to investigate the characteristics of electromagnetic flowmeter in two -phase flow, an AC electromagnetic flowmeter was designed and manufactured. In various flow conditions, the signals and noises from the flowmeter were obtained and analyzed by comparison with the observed flow patterns with a high speed CCD camera. The experiment with the void simulators in which rod shaped non-conducting material was used was carried out to investigate the effect of the bubble position and the void fraction on the flowmeter. Based on the results from the void simulator, two -phase flow experiments encompassed from bubbly to slug flow regime were conducted. The simple relation $\Delta$ $U_{TP}$ = $\Delta$ $U_{SP}$ (l-$\alpha$) was verified with measurements of the potential difference and the void fraction. Due to the lack of homogeneity in a rent two -phase flow, the discrepancy between the relation and the present measurement was slightly increased with void fraction and also liquid volumetric flux jf. Whereas there is no difference in the shape of the raw signal between single-phase flow and bubbly flow, the signal amplitude for bubbly flow is higher than that for single -phase flow at the same water flow rate, since the passage area of the water flow is reduced. In the case of slug flow, the phase and the amplitude of the flowmeter output show dramatically the flow characteristics around each slug bubble and the position of a slug bubble itself. Therefore, the electromagnetic flowmeter shows a good possibility of being useful for identifying the flow regimes.ul for identifying the flow regimes.