• 한국자동차공학회논문집
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• 제9권2호
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• pp.50-58
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• 2001

The purpose of this research is to obtain the information of the development process of a vaporizing GDI spray using exciplex fluorecence method. Fluorobenzene/DEMA system was used as the exciplex-forming dopants. The 2-D spray images of liquid and vapor phases were acquired, and the behavior of both phases was analyzed by the image processing. The experiment was performed at the three different ambient perssures and the ambient temperature of 273K and 473K. As the result of this work, it was found that the development characteristics of GDI spray have stronger effect on the ambient pressure than on the ambient temperature. With an increase of ambient pressure, the distribution of vapor phase was decreased and the concentration of that was denser. Two regions, namely cone and mixing regions could be identified from those resulrs.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.1372-1377
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• 2008

Since metallic foam will increase the performance of heat exchanger, it have caused many researcher's attention recently. Our research base on the model that metallic foams applied to heat exchanger. In this case, there is three kind of heat transfer mechanisms, heat conduction in fibers, heat transfer by conduction in fluid phase, and internal heat change between solid and fluid phases. In this paper, we first discuss the acceptance of applying thermal equilibrium among the two phases. then to calculate the dimensionless temperature profile along 7 metallic foams. The 7 samples have different characteristics, such as area ratio, effective conductivity, porosity, etc.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1998년도 Advances in Ginseng Research - Proceedings of the 7th International Symposium on Ginseng -
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• pp.31-39
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• 1998

We have investigated the antinociceptive efficacy of ginseng saponins in mice using l% formalin, which induce two phases of pain (acute and tonic pains) and is known to induce a clinically related pain. Ginseng total saponins (GTS) relieved both phases of pain with EDso of 162 mghg for acute and 92 mg/kg for tonic pain, respectively. Both protopanaxadiol (PD) and protopanaxatriol (PT) saponins did not attenuated acute phase of pain but relieved tonic phase of pain with EDso of 45 mg/kg for PD saponins and 105 mghg for PT saponins, respectively. Moreover, ginsenoside Rc, Rd, and Re among representative ginsenosides such as Rbl, Rc, Rd, Re and Rgl relieved slightly but significantly acute phase of pain and strongly attenuated tonic phase of pain but Rf relieved only tonic phase of pain. However, PD and PT saponins, and the individual ginsenosides tested except GTS did not greatly attenuate thermal noxious pain (tail-flick test). These results suggest that single ginsenoside or mixture of various ginsenosides mainly induce differential antinociception in mice.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1590-1593
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• 2002

We propose a dynamic location management scheme and named it Virtual Dynamic Location Area(VDLA) scheme. It allocates LA on the basis of terminal mobility, VDLA consists of two phases: VLA allocation and final LA selection phases. In the first phase it allocates primary and secondary VLAs to the terminal. In the second phase the terminal selects one of them using LA selection criterion. Cost analysis of the proposed scheme is peformed and its location management cost is compared with those of FLA and DBLA.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1988년도 추계학술대회 논문집
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• pp.98-101
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• 1988

The material system (Bi$\sub$0.7/Pb$\sub$0.3/)Sr$_1$Ca$_1$Cu$\sub$1.8/Ox forms, at 845$^{\circ}C$, two major phases having a high Tc(100K) and a low Tc(∼70K) both of which consists of platelets and a non-superconducting minor phase which has rod-like shape and isolated by the major phases. As the sintering period increases, the amount of high Tc phase increases accompanying the decrease in low Tc phase while the amount of the non-superconducting phase is sintering period independent, resulting in a superconductor with Tc of 100K. Changes in compositions of each phase also occur during sintering due to evaporation of bismuth and lead.

• 대한화학회지
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• 제57권6호
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• pp.684-690
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• 2013

Since a glycerol molecule has three active sites, two ${\alpha}$ and one ${\beta}$ hydroxyl groups; it undergoes condensation by releasing water molecules to produce linear, nonlinear and heterocyclic oligomers. The Gibbs free energy (G), enthalpy (H) and internal energy (E) of 7 diglycerol, 15 triglycerol and 23 tetraglycerol isomers were calculated at B3LYP level of theory using 6-311++G(d, p) basis set, in both gas and aqueous phases. Linear oligomers, ${\alpha}{\alpha}$-diglycerol, ${\alpha}{\alpha}$, ${\alpha}{\alpha}$-triglycerol and ${\alpha}{\alpha}$, ${\alpha}{\alpha}$, ${\alpha}{\alpha}$-tetraglycerol, were found to be the most stable oligomers in aqueous phase. It was found that the stability of cyclic oligomers decreases as the size of their rings increases. Cyclic oligomers are produced by dehydration of the acyclic ones which is an endothermic reaction while its ${\Delta}G$ is negative. The dehydration reaction is less endothermic in aqueous phase.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.284-287
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• 2001

In the System-integrated modular advanced reactor(SMART), the motor for Control element drive mechanism(CEDM) requires high density power and simple drive mechanism to reduce volume because of restriction by install-space and must satisfy the reactor operating circumstances with high pressure and temperature. To Maximize the characteristics of the TFM, we chose the asymmetric bridge converter as the driving system for TFM. Because two switching devices are connected in series with the stator winding of each phases in the asymmetric bridge converter all the phases are not affected by another phase but controlled independently. Also, this converter has many advantages that the various control methods can be adopted, it is easy to control, and that in case that the switching devices of a phase are damaged, the affects can be minimized.

• 대한기계학회논문집B
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• 제30권5호
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• pp.422-429
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• 2006

Resolved simulations are presented fur gravity current flows aiming at studying their spreading rate. The simulations are performed for two extreme configurations such as planar and cylindrical and for 3 different Grashof numbers: $10^5,\;1{\times}10^6\;and\;10^7$. Varying the size of the heavy fluid release, the study is performed for several phases of spreading, namely acceleration, slumping and inertial phases. For the simulations, efficient spectral multi-domain code is used. From the simulations results it is concluded that 2-D results predicts well the mean front velocity during the slumping phase, but fails to predict it during the inertial phase of spreading. It is also observed that the vortex dynamics of the flow is not reproduced well by the 2-D simulation.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2003년도 춘계학술발표회 초록집
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• pp.31-32
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• 2003

In the Present study, the effect of galvannealing conditions on the phase distribution of the Zn-Fe intermetallic phases in the coating layer of the galvannealed steel sheets(GA) was investigated in an interstitial free steel and two kinds of high strength steels. The composition profiles of the coating layers were analyzed using AA and EDS analysis, and the distribution of the intermetallic phases was examined with the aids of X-ray diffraction. On the basis of the pole figure and OIM analyses, it was clarified that the preferred orientation of the $\zeta$ phase depended on the development of the $\gamma$-fibre texture in the substrate.

• Bulletin of the Korean Chemical Society
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• 제11권2호
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• pp.118-123
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• 1990

X-ray photoelectron spectra have been obtained and comparisons have been made for 1-2-3 and 2-1-1 phases of YBaCuO compounds. The photoelectron binding energies of all the constituent elements are consistently larger for the 2-1-1 phase than for the 1-2-3 phase. The peak intensities reflect different stoichiometries of the two phases. For the superconducting 1-2-3 phase, its degradation in air and interaction with water and carbon dioxide were examined by taking core level spectra of all the elements. It appears that yttrium is the most affected by exposure to air, since it undergoes a rapid change to carbonate when water and subsequently carbon dioxide are introduced.