• Proceedings of the Earthquake Engineering Society of Korea Conference
• /
• 2006.03a
• /
• pp.345-350
• /
• 2006

If a structure is founded on the ground saturated with pore water, then the ground should be modeled as a saturated two-phase porous medium for accurate earthquake response analysis. In this study, a 3-dimensional transmitting boundary is developed for modeling of far field using u-U formulation for water-saturated transversely isotropic layered stratum. The developed transmitting boundary is verified by comparing the dynamic stiffness of rigid square foundation on water-saturated isotropic layered stratum with the case of using equivalent single-phase medium model.

• Journal of the Korean Applied Science and Technology
• /
• v.10 no.2
• /
• pp.11-18
• /
• 1993

Contents of vitamin $D_3$ and 25-OH-vitamin $D_3$ in marine animal products(20 species) were determined by HPLC. The isomers of vitamin D, $D_2$ and $D_3$, were not clearly separated on a reversed phase, ${\mu}$ Bonda Pak, with 20% methanol-acetonitrile, and on a normal phase, Zorbax SIL. with 0.4% isopropanol-hexane, but 25-OH-vitamin $D_2$ and-$D_3$ were separated on either ${\mu}$ Bonda Pak with 10% methanol-acetonitrile, or on Zorbax SIL with 2.2% isopropanol-hexane, respectively. Although levels of vitamin $D_3$ and 25-OH-vitamin $D_3$ varied remarkably according to species, their average value(fish : $l,l87{sim}36,007$ I.U/sample 100g, mussel : $58{\sim}1,706$ I.U/sample 100g, pickle: $1,208{\sim}79,358$ I.U/sample 100g) was greatly higher than that of meat($80{\sim}100$ I.U/sample 100g) and dairy products($400{\sim}800$ I.U/sample 100g). Fatty tissues of fish and pickled fish intestines contained high level of vitamin $D_3$ and 25-OH-vitamin $D_3$, while the clam and mussel known to have various kinds of sterol including ${\Delta}^7$-sterol showed very low levels of vitamin $D_3$ and its derivative.

• Proceedings of the Ginseng society Conference
• /
• 2002.10a
• /
• pp.376-384
• /
• 2002

Object To find out which of the 27 ginsenosides isolated from Panax ginseng C.A. Mey that may inhibit the proliferation of human osteosaocoma cell line $U_2OS$. Methods Effects of each individual ginsenoside on the proliferation of $U_2OS$ cell were studied by determining the viability of cancer cells during culture with or without the presence of the test compound. DNA assay was determined by flow cytometry. Results Ginsonosides -Ro, $-Rh_l,\;-Rh_2,\;-F_1\;and\;-L_8$ at concentrations of 5 ,umol/L could obviously suppress the proliferation of $U_2OS$ cells while ginsenosides $-Rg_1,\;-F_3,$ -Rf, PPT and PT significantly inhibited the cancer cells. Flow cytometry revealed that ginsenosides $-Ro,-Rg_1-Rf,-F_1-Rh_2,PPT$ and PT induced cell cycle arrest at $G_0/G_1$ phase with obvious decrease of cell count at Sand $G_2+M$ phase, Moreover, ginsenosides $-Rf_1,-Rg_1,\;-F_1$ and PPT induced significantly high rates of cell death as compared with the control. Conclusion These data suggested that ginsenosides inhibited $U_2OS$ proliferation Via cell cycle arrest or induction of cell death.

• Nuclear Engineering and Technology
• /
• v.55 no.4
• /
• pp.1300-1309
• /
• 2023

Simulated debris was synthesized using UO₂, Zr, and stainless steel and a heat treatment method under inert or oxidizing conditions. The primary U solid phase of the debris synthesized at 1473 K under inert conditions was UO₂, whereas a (U, Zr)O₂ solid solution formed at 1873 K. Under oxidizing conditions, a mixture of U₃O₈ and (Fe, Cr)UO₄ phases formed at 1473 K, whereas a (U, Zr)O_2+x solid solution formed at 1873 K. The leaching behavior of the fission products from the simulated debris was evaluated using two methods: the irradiation method, for which fission products were produced via neutron irradiation, and the doping method, for which trace amounts of non-radioactive elements were doped into the debris. The dissolution behavior of U depended on the properties of the debris and aqueous solution for immersion. Cs, Sr, and Ba leached out regardless of the primary solid phases. The leaching of high-valence Eu and Ru ions was suppressed, possibly owing to their solid-solution reaction with or incorporation into the uranium compounds of the simulated debris.

• Journal of Ocean Engineering and Technology
• /
• v.12 no.2 s.28
• /
• pp.147-152
• /
• 1998

In this study turbine flowmeters were used to predict volumetric flow rate of each phase in two-phase, gas-liquid, flowing in a vertical tube. To determine volumetric flow rates of two-phase, air-water, flowing vertically upward through the polycarbonate tube(57mm ID-inside diameter), two turbine flow meters were used. For void fraction measurements, two gamma densitometers were used at each location of the turbine flow meter, one at the upstream and the other at the downstream. It was determined that the turbine flowmeter's outputs were a function of actual volumetric flow rate of each of the two phases. A two-phase flow model was developed.

• Journal of the Korean Society for Precision Engineering
• /
• v.18 no.11
• /
• pp.155-160
• /
• 2001

To achieve high precision cutting as well as production capability in the machine tool, it is needed to develop excellent rigidity statically, dynamically and thermally as well. In order to predict the qualitative behavior of a machine tool, simultaneous analysis of mechanics and heat transfer is required. Generally, machine tool designers have solved designing problems based on partial estimation of the specified rigidity. This study clears the inter-relationship between therm, and propose multi-phase optimization of machine tool structure using a genetic algorithm. The multi-phase solution method is consists of a series of mechanical design problem. At this first phase of static design problem, multi-objective optimization for the purpose of minimization of the total weight and static compliance minimization is solved using the Pareto Genetic Algorithm.

• Macromolecular Research
• /
• v.14 no.1
• /
• pp.45-51
• /
• 2006

We conducted simultaneous, small-angle, X-ray scattering/differential scanning calorimetry (SAXS/DSC) and simultaneous, wide-angle, X-ray scattering (WAXS)/DSC measurements for a polymer blend of poly($\varepsilon$-caprolactone)/poly(ethylene glycol)(PCL/PEG). The time-dependent SAXS/DSC and WAXS/DSC results, measured while the system was quenched below the melting temperature of PCL from a melting state, revealed the competitive behavior between liquid-liquid phase separation and crystallization in the polymer blend. The time-dependent structural evolution extracted from the SAXS/WAXS/DSC results can be characterized by the following four stages in the PCL crystallization process: the induction (I), nucleation (II), growth (III), and late (IV) stages. The influence of the liquid-liquid phase separation on the crystallization of PCL was also observed by phase-contrast microscope and polarized microscope with 1/4$\lambda$ compensator.

• The Transactions of the Korean Institute of Electrical Engineers B
• /
• v.48 no.8
• /
• pp.440-447
• /
• 1999

This paper proposes a control method for three-phase PWM rectifier with only single current sensor in DC link side. A PWM modulation strategy for reconstructing three phase currents from the DC link current is given. The states of the retifier switch are modified so that all phase currents can be reconstructed in a switching period although one or two of active vectors is applied only for a short time. Therefore, a new current control using an adjustment scheme of the modulation signal for three-phase PWM rectifier will be discussed, and verified the experimental results.

• The Korean Journal of Zoology
• /
• v.36 no.2
• /
• pp.277-284
• /
• 1993

A possible involvement of maturation promoting factor (nfPF) in the two-cell block phenomenon was studied by fusion experiments. Germinal vesicle (GlF) ooeyte was fused with a blastomore from late or blocked 2-cell mouse embryos. and germinal vesicle breakdoum (GVBD) of fused GV oocvtes in the presence of dbcAMP (100$\mu$g/ml) was scored as an index of MPF aniviD. GnD was induced approximately 30% by fusion of a blastomere derived from late 2-cell embryos, but not from blocked 2-cell embryos. The rate of GVBD was changed when GV oocyte was fused with a blastomere from late 2-cell embryos which were treated with u-amanitin, puromvcin or colcemid before and after hsion: Treatment of late 2-cell embryos with puromycin (50 Is/mll but not with u-amanitin (100 Is/ml) clearly inhibited GVBD, indicating that do novo protein synthesis maw be required for the appearance of MPF activity in late 2-cell embryos. Treatment of late 2-cell embryos w기h colcemid (0.1 Is/mll doubled GVBD, presumably due to the maintenance of metaphase or mitotic phase. SDS-PAGE and twoiimensional electrophoresis revealed that there was no difference in protein synthetic pattern in late and blocked 2-cell embryos, but three phosphoproteins with 27, 35 and 46 M)a, presumsblv M-phase components were phosphorylated in late 2-cell embryos but not in blocked 2-cell embryos. It seems then that MPF activity is closely related to phosphorylstion of M-phase components in late 2-cell embryos.

• Journal of Ginseng Research
• /
• v.5 no.1
• /
• pp.65-72
• /
• 1981

In this experiment, observations were made on the effects of ginseng saponin, one of the major components of Korean ginseng (Panax ginseng, C. A. Meyer) root, on the membranes of microorganism (E. coli K-12), the concentration of intracelluar and extracellular cycle AMP therein, and uptake of U-14C-glucose. When the E. coli were grown on media containing 0.1% ginseng saponin, the growth was faster than for that of the control by about 30 minutes. The lysis of E. coli grown on the ginseng saponin medium increased to about double that of the control in the stationary phase. And the amount of protein and lipopolysaccharides in the outer cell meberances increased 25% and 80% respectively in comparison with the control. By electron microscope observation, it was shown that the periplasmic region of the E. coli grown on the ginseng saponin medium was widened it was observed that the cellular cyclic AMP content of the E. coli increased significantly to the hightest levels between the late exponential phase and early stationary phase. The total cyclic AMP content of E. coli grown on the ginseng saponin medium decreased about 50% when compared to that of the control.