• Korean journal of food and cookery science
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• v.11 no.4
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• pp.365-369
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• 1995

The content ratios of gingerol in 4 fractions (hexane, ether, ethylacetate and hexane-ether (1:1, v/v) fraction) extracted from ginger (Zingiber officinale Roscoe) were analyzed using high performance liquid chromatography (HPLC). The content ratios of 6-gingerol in 4 fractions were hexane fraction; 49.5％, ether fraction; 20.74％, ethylacetate fraction; 21.43％ and hexane-ether (1 : 1, v/v) fraction; 93.70％. Antioxidant activities of soybean oil added 0.2％ of each ginger fraction and 0.02％ of BHT were determined by peroxide value during storage at 45$^{\circ}C$. And relative antioxidant effectiveness (RAE) was calculated as the ratio of the induction period of a given substrate oil to that of a control oil. RAE of each fraction was hexane fraction; 2.60, ether fraction; 2.33, ethylacetate fraction; 2.07 and hexane-ether (1 : 1, v/v) fraction; 2.75, BHT; 1.74. Inhibition effect of each fraction on the rat liver microsomal lipid peroxidation showed hexane fraction; 93％, ether fraction; 92％, ethylacetate fraction; 86％ in 350 g/$m\ell$ and hexane-ether (1 : 1, v/v) fraction; 89％ in 20 g/$m\ell$.

• Journal of Periodontal and Implant Science
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• v.31 no.4
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• pp.833-846
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• 2001

Recently, use of natural medicine is getting more attention, and some of them are believed to be effective in　the treatment of periodontitis. Among them, the seeds of safflower(Carthamus tinctrorius L.) have been proven to be effective through its use in bone diseases such as fracture and osteoporosis. During the last few years, studies using the seeds of safflower gown in Korea have been active, and it has been reported that safflower seed extract increase the proliferation and the alkaline phosphatase(ALP) activity of human periodontal ligament fibroblast(hPDLF), osteoblast, and that they promote the mineralization process. In animal studies, when safflower seed extract were administered orally new bone formation was promoted. Recently, in an effort to find out the most effective osteogenic components, among many components of the safflower seed, various safflower seed fraction extracts were obtained by multistep extraction of the safflower components using various solvents. Among these, saf-M-W fraction extracted by methanol and water was most effective in increasing osteogenic potential of osteoblasts. In this study, the effect of safflower seed fraction extract, saf-M-W, on the growth and differentiation of hPDLF and MC3T3-E1 cell was investigated. The toxicity of saf-M-W on both cells was measured using M'IT(3-(4,5dimethylthiazol-2-y1)-2,5-diphenyl tetrazolium bromide) test, and ALP activity was measured using the colorimetric assay of hPDLF. In addition, in MC3T3-El cells, the expression of ALP, bone sialoprotein(BSP) mRNA was observed using Northern blot, and the mineralized nodule formation Was observed using von Kossa stain and phase-contrast microscope. 1. In concentrations below $10{\mu}g/ml$, saf-M-W didn't show any toxicity on hPDLF and MC3T3-El cell. 2. The change in saf-M-W concentration had no effect on the ALP activity of hPDLF. 3. In MC3T-E1 cells, mRNA expressions of ALP and BSP were greater in the experimental group treated with $10{\mu}g/ml$ concentration of saf-M-W compared with the control group. 4. In MC3T3-El cells, abundance of mineralized nodules were formed in the experimental group treated with $10{\mu}g/ml$ Concentration of saf-M-W, while no mineralized nodule was formed in the control group. These results suggest that safflower seed fraction extract, saf-M-W. didn't show any toxicity on hPDLF and MC3T3-E1 cell at concentrations below $10{\mu}g/ml$ and effectively enhanced the differentiation and osteogenic potential of MC3T3-El cell.

• The Korean Journal of Pharmacology
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• v.12 no.1
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• pp.7-14
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• 1976

Aconiti tuber butanol fraction shows positive inotropic effect on the isolated atrium of rabbit heart. To investigate the mechanism, the effect on microsomal ATPase activity of rabbit heart is observed. The microsomal fraction which contains the $Na^+$- and $K^+$-activated ATPase in the presence of $Mg^{++}$ is isolated from the left ventricle of rabbit heart. The microsomal ATPase activity is maximally stimulated at $Na^+$ and $K^+$ concentration of 100 mM and 10 mM respectively. Microsomal $Na^+-K^+$-activated ATPase is inhibited by ouabain and Aconiti tuber butanol fraction. Ouabain and Aconiti tuber butanol fraction depress $Na^+$-stimulation on microsomal ATPase activity, and the inhibitory effects are not completely reversed at $Na^+$ concentration of 300 mM. Also, $K^+$-stimulation on microsomal ATPase activity is inhibited by ouabin and Aconiti tuber butanol fraction and the inhibitions are not compeletely reversed at $K^+$ concentration of 30 mM. It is, therefore, suggested that the inhibitory effect of Aconiti tuber butanol fraction on the microsomal ATPase activity may contribute to leading to the positive inotropic effect.

• Nuclear Engineering and Technology
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• v.54 no.3
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• pp.975-983
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• 2022

A four-layered W/Cu functionally graded material (FGM) (W90% + Cu10%/W80% + Cu20%/W70% + Cu30%/W60% + Cu40%, wt.% fraction) and a four-layered diamond/W-Cu FGM (W90% + Cu10%/W80% + Cu20%/W70% + Cu30%/W55% + Cu40% + diamond5%, wt.% fraction) were fabricated by microwave sintering. The thermal conductivity and thermal shock resistance of diamond/W-Cu FGM and W-Cu FGM were investigated. The morphologies of the diamond particles and different FGMs were analyzed using AFM, SEM, EDS, and TEM. The results show that a 200 nm rough tungsten coating was formed on the surface of the diamond. The density of the tungsten-coated diamond/W-Cu FGM, obtained by microwave sintering at 1200 ℃ for 30 min, was 94.66%. The thermal conductivity of the fourlayered diamond/W-Cu FGM was 220 W·m^-1·K^-1, which is higher than that of the four-layered W/Cu FGM (209 W m^-1 K^-1). This indicates that adding an appropriate amount of tungsten-coated diamond to the high Cu layer W/Cu FGM improves the thermal conductivity of the composite. The diamond/W-Cu FGM sintered at 1200 ℃ for 10 min exhibited better thermal shock resistance than diamond/W-Cu FGM sintered at 1100 ℃ for 10 min.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.50.1-50.1
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• 2017

We present our study of the correlation between star formation rate(SFR) and merging activities of nearby galaxies(d<150Mpc). Our study uses 265 UV-selected galaxies which are not classified as AGN. The UV selection is made using the GALEX Atlas of Galaxies (Gil de Paz+07) and the updated UV catalog of nearby galaxies (Bai+15). We use deep R band optical images reaching to $1{\sigma}$ surface brightness detection limit ${\sim}27mag/arcsec^2$ to classify merger features by visual inspection. We also estimated unobscured SFR($SFR_{NUV}$) and obscured SFR($SFR_{W4}$) using Near-UV continuum and 22 micron Mid-IR luminosity respectively as a indicator of star forming activity. The fraction of galaxies with merger features in each SFR bin is obtained to see if how the fraction of galaxies with merging features($F_m$) changes as a function of SFR. As a result, for 203 late type galaxies(LTGs), we found that merger fraction increases from ~8% up to 50% with $SFR_{W4}$, while for 229 LTGs $SFR_{NUV}$ shows relatively consistent fraction(~18%) of merger fraction. For early type galaxies(ETGs), we could also find no significant correlation between $F_m$ and SFR(both $SFR_{NUV}$ and $SFR_{W4}$). This result suggests that a main driver of star forming activity of UV bright galaxies, especially for obscured late types, is mergers.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.10
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• pp.2675-2685
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• 1994

A study has been conducted to provide the experimental information for the velocity and temperature profiles of steam-air mixutre and to investigate their roles on the film condensation with wavy interface. Saturated gas mixture of steam-air was made to flow through the nearly horizontal$(4.1^{\circ})$ square duct of 0.1m width and 1.56m length at atmospheric pressure, and was condensated on the bottom cold plate. The air mass fraction in the gas mixture was changed from zero(W =0, pure steam) to one(W =1, pure air), and the bulk velocity was varied from 2 to 4 m/s. Water film was injected concurrently to investigate the effect of wavy interface on the condensation. The velocity and temperature profiles were measured by LDA system and thermocouples along the three parameters ; air mass fraction, mixture velocity and film flow rate. The profiles moved toward the interface with increasing steam mass fraction, mixture velocity and film flow rate. The Prandtl and Schmidt numbers were near one in the present experimental range, however there was no complete similarity between the velocity and temperature profiles of gas mixture. And the heat transfer characteristics and interfacial structure were coupled with each other.

• Journal of the Korean earth science society
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• v.39 no.3
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• pp.228-240
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• 2018

Solar energy is calculated using meteorological (14 station), ceilometer (2 station) and microwave radiometer (MWR, 7 station)) data observed from the Weather Information Service Engine (WISE) on the Seoul metropolitan area. The cloud optical thickness and the cloud fraction are calculated using the back-scattering coefficient (BSC) of the ceilometer and liquid water path of the MWR. The solar energy on the surface is calculated using solar radiation model with cloud fraction from the ceilometer and the MWR. The estimated solar energy is underestimated compared to observations both at Jungnang and Gwanghwamun stations. In linear regression analysis, the slope is less than 0.8 and the bias is negative which is less than $-20W/m^2$. The estimated solar energy using MWR is more improved (i.e., deterministic coefficient (average $R^2=0.8$) and Root Mean Square Error (average $RMSE=110W/m^2$)) than when using ceilometer. The monthly cloud fraction and solar energy calculated by ceilometer is greater than 0.09 and lower than $50W/m^2$ compared to MWR. While there is a difference depending on the locations, RMSE of estimated solar radiation is large over $50W/m^2$ in July and September compared to other months. As a result, the estimation of a daily accumulated solar radiation shows the highest correlation at Gwanghwamun ($R^2=0.80$, RMSE=2.87 MJ/day) station and the lowest correlation at Gooro ($R^2=0.63$, RMSE=4.77 MJ/day) station.

• Korean Journal of Metals and Materials
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• v.48 no.7
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• pp.589-597
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• 2010

In the present study, the effect of variation in alloying elements on the carbide formation behavior during casting and homogenization treatment of M2 high speed steels was investigated. M2 high speed steels of various compositions were produced by vacuum induction melting. Contents of C, Cr, W, Mo, and V were varied from the basic composition of 0.8C, 0.3Si, 0.2Mn, 4.0Cr, 6.0W, 5.0Mo, and 2.0V in weight percent. Homogenization treatment at $1150^{\circ}C$ for 1.5 hr followed by furnace cooling was performed on the ingots. Area fraction and chemical compositions of eutectic carbide in as-cast and homogenized ingots were analyzed. Area fraction of eutectic carbide appeared to be higher in the ingots with higher contents of alloying elements the area fraction of eutectic carbide also appeared to be higher on the surface regions than in the center regions of ingots. As a result of the homogenization treatment, $M_2C$ carbide, which was the primary eutectic carbide in the as-cast ingots, decomposed into thermodynamically stable carbides, MC and $M_6C$. The latter carbide was found to be the main one after homogenization. Fine carbides uniformly distributed in the matrix was found to be MC type carbide and coarsened by homogenization.

• Korean Journal of Pharmacognosy
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• v.29 no.4
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• pp.391-395
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• 1998

The phagocytic activity of murine peritoneal macrophages was determined by lucigenin chemiluminescence with luminometer and engulfment of fluorescein-conjugated E. coli particles. 70% MeOH extract of Lithospermi Radix was fractionated successively with hexane, methylene chloride, n-BuOH and water. The water fraction (m.w. 500 to 1,000) enhanced the lucigenin chemiluminescence and the engulfment of fluorescein-conjugated E. coli particles in murine peritoneal macrophages. The water fraction suppressed the production of nitric oxide in the macrophages. These results suggest that an active fraction of phagocytosis in Lithos-permi Radix is the water fraction and the molecular weight is 500 to 1,000.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.320-325
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• 2010

A multiphase CFD analysis is performed to investigate the effect of near-wall grid for simulating a subcooled boiling flow in vertical tube. The multiphase flow model used in this CFD analysis is the two-fluid model in which liquid(water) and vapor(steam) are considered as continuous and dispersed fluids, respectively. A wall boiling model is also used to simulate the subcooled boiling heat transfer at the heated wall boundary. The diameter and heated length of tube are 0.0154 m and 2 m, respectively. The system pressure in tube is 4.5 MPa and the inlet subcooling is 60 K. The near-wall grid size in the non-dimensional wall unit ($y_{w}^{+}$) was examined from 64 to 172 at the outlet boundary. The CFD calculations predicted the void distributions as well as the liquid and wall temperatures in tube. The predicted axial variations of the void fraction and the wall temperature are compared with the measured ones. The CFD prediction of the wall temperature is shown to slightly depend on the near-wall grid size but the axial void prediction has somewhat large dependency. The CFD prediction was found to show a better agreement with the measured one for the large near-wall grid, e.g., $y_{w}^{+}$ > 100.