• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.9
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• pp.1101-1108
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• 2008

This study was carried out to compare the physiological activities of the extracts from Korean and Chinese Viola mandshurica W. Baker. The water extract from leaves of Chinese V. mandshurica exhibited the highest extraction yields of 30.45 g/100 g and the highest content of total flavonoids as 102.30 mg/g. Also, its ethanol extract showed the best content of polyphenol compounds as 136.16 mg/g. The leaf extract of Korean V. mandshurica produced higher electron donating abilities (EDA) of 92.69% (KLW) and 93.61% (KLE) than the other fractions. The strongest SOD-like activity was shown in the ethanol extract from Korean leaves of 17.28% at the concentration of 1.0 mg/mL. The nitrite scavenging abilities (NSA) of the leaf extracts of V. mandshurica from China were intense over 50% at pH 1.2 and 3.0. In the results of inhibitory rates of xanthine oxidase (XO), both ethanol extracts from Korean and Chinese leaves were higher than the other fractions as 98.67% and 93.80% respectively. Effect of tyrosinase inhibition was the highest in the water extract (45.04%) of Chinese leaves, followed by its ethanol extract (31.36%). The results of EDA, SOD-like activity and XO inhibition of the leaf extracts from Korean V. mandshurica were higher than those of Chinese, on the other hand, determinations on total polyphenol contents, NSA and tyrosinase inhibition were higher in those of Chinese.

• Microbiology and Biotechnology Letters
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• v.6 no.4
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• pp.155-159
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• 1978

Phenol utilizing yeast No. 558 isolated from soil sewage sediment was able to use substantial amount of phenol as the sole carbon source, and the biomass productivity by this organism was very excellent. This organism could grow well in 1000 ppm of phenol concentration, the maxim-um specific growth rate obtainable at pH 5.0, 3$0^{\circ}C$ was 0.27/hr., and the biomass yield coefficient Y vs. consumed phenol was 3.2. Maximum production rate of biomass was observed at 35$^{\circ}C$, pH 3.5 to pH 4.5, and the addition of the 0.005~0. 01% yeast extract was the most effective. Addition of HgCl$_2$ and phenyl hydrazine, inhibitors of oxide-reductase, in the phenol containing cultural liquid caused this organism no-growth at the concentration of 10$^{-5}$ M, 10$^{-3}$ M respectively. This organism could utilize not only phenol but catechol, resorcinol and benzidine.

• Journal of the Korean GEO-environmental Society
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• v.12 no.11
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• pp.59-64
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• 2011

Clogging in drainage pipe is one of the important problems, so it needs a remedy urgently. Recently, scale in drainage pipe is removed by water jet cleaning and other treatment. But these treatments need much cost and regular management. The principal component of scale in drainage pipe is $CaCO_{3}$. It was observed the setting of $CaCO_{3}$ by some kind of analysis such as SEM, XRD, visual and weight measuring analysis to solve these problems and prevent setting formation in drainage pipe. As a result, in case of magnetic, particle shape of $CaCO_{3}$ is changed Aragonite from Calcite. Also in case of Quantum Stick, the amount of scale is reduced by expert inspector's result. As a whole, Magnetic treatment and Quantum Stick have the effect for protecting of scale precipitation.

• Journal of Korean Society of Forest Science
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• v.46 no.1
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• pp.21-28
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• 1980

Strobilus initiation in grafted, 18-year-old slash pine (Pinus elliottii var. elliottii) in a seed orchard was examined in relation to morphological and anatomical characteristics of shoots. Needle weight (total fresh weight of needles per shoot produced during the current growing season) was the most closely related single variable to the number of female flowers produced the following year ($R^2=0.41$). The number of female and male strobili (per shoot) produced the following year was positively and negatively correlated, respectively, with the total weight of current-year needles per shoot. A transition from male to female flowering was associated with increasing vigor (number of needles) of the shoot. Vegetative buds in the upper parts of the crown of poor-flowering trees showed more advanced growth of vascular tissues compared with female-or male-producing buds, indicating a strong favor for vegetative growth.

• Microbiology and Biotechnology Letters
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• v.14 no.6
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• pp.473-478
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• 1986

In order to elucidate the patterns of natural oils and fats assimilation by microorganisms, lipases properties of yeast and bacterium strain, Torulopsis candia Y-128 and Acinetobacter calcoaceticus KB-2, which could assimilate palm oil efficiently, were investigated. T candida Y-128 attached palm oil droplets directly, and assimilated unsaturated fatty acid more easily than saturated acids liberated by the action of its lipase. Lipase of A. calcoaceticus KB-2 was extracellular and appeared quickly from the beginning of log phase of growth, whereas lipase of f candida Y-128 appealed intracellular. The lipases of two strains seem to be only enough to utilize the lipid materials for their own growth, without accumulation of lipases in the culture broth. Lipases of the strains have 1 (3-)-positional specificities on triglycerides. The patterns of palm oil assimilation showed that two strains attached droplets of lipid materials directly and split off fatty acids at 1 (3-)-position of triglycerides first, and assimilated the reaction products via fatty acids metabolic pathway.

• Journal of the Korean Magnetics Society
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• v.2 no.2
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• pp.145-149
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• 1992

The characteristics of electromagnetic devices with permanent magnet depends greatly on the remanence pattern of permanent magnet. So, it is necessary to analyze the pattern of remanence in permanent magnet. This paper presents a finite element analysis of magnetizer considering the nonlinearity and anisotropy of yoke and magnet in magnetizer. The distributions of magnetizations are obtained according to the variations of magnetizing currents for two kinds of magnetizers with different magnetizing poles. It is found that the excessive magnetizing current results in the reduction and polarity reversion of magnetization in the multi-pole magnetizing system where the pole angle is too small. During the design and analyzing of multi-pole magnetizer, it must be considered that there exists an optimal value of magnetizing current and pole angle of magnetizer.

• Journal of the Korean Geotechnical Society
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• v.22 no.7
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• pp.65-72
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• 2006

This study is about the estimation of the mechanical properties of cement grout material using a magnetic field treated water instead of tap water. The water that passed through a magnetic system is called MFTW. Similar research indicates that 5% of cement dosage can be saved by decreasing bleeding of concrete and improving resistance to freezing. The reason why MFTW can improve characteristics of concrete can be explained by molecular structure of water. Magnetic force makes water clusters into single molecule or small ones. Hence, the activity of water is improved by the magnetic force. While hydration of cement particles is on progress, the MFTW can penetrate the core region of cement particles more easily. Therefore, the hydration can be carried out more efficiently and the compression strength of concrete is highly improved. The sample of the sodium silicate cement grout's homogel using the MFTW results in highly compressive strength increases in compressive strength approximately from 20% to 50%.

• Journal of the Korean Society for Nondestructive Testing
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• v.16 no.3
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• pp.162-173
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• 1996

Dry magnetic particle inspection(MPI) was performed to detect the surface defects of steel ingot cast billets. Magnetic properties of several materials were characterized by the measurement of the B-H hysteresis curve. The inspection results were evaluated in terms of the magnetizing current, temperature, and the amount of magnetic particles applied to billets. Magnetic flux leakage near the defect site of interest was measured and compared with the results of calculation by the finite element method in the case of direct magnetizing current. Direct and alternating magnetizing currents for materials were deduced by the comparison of the inspections. Results of the magnetic particle inspection by direct magnetizing current were compared with those of finite element method calculations, which were verified by measuring magnetic leakage flux above the surface and the surface defects of the material. For square rods, due to the geometrical effect, the magnetic flux density at the edges along the length of the rods was about 30% of that at the center of rod face for a sufficiently large direct magnetizing current, while it was about 70% for an alternating magnetizing current. Thus, an alternating magnetizing current generates rather uniform magnetic flux density over the rods, except for the region on the face across about 10 mm from the edge. The attraction of the magnetic particle by the magnetic leakage field was nearly independent of the surface temperature of the billets up to $150^{\circ}C$. However, the temperature should have been limited below $60^{\circ}C$ for an effective fixing of gathered magnetic particles to the billet surface using methylene chloride. We also found that the amount of applied magnetic particles tremendously affected the detection capability.

• Korean Journal of Animal Reproduction
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• v.23 no.2
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• pp.133-139
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• 1999

This study was carried out to investigate in vitro/in vivo development of vitrified-thawed immature mouse oocytes. Immature mouse oocytes were vitrified with EFS40 (40% ethylene glycol, 18% ficoll and 0.5 M sucrose). Thawed oocytes were matured for 16 hr in vitro. Matured oocytes with the first polar body were fertilized with the concentration of 1~2$\times$10$^{6}$ $m\ell$ of epididymal sperm. After fertilization, cleavage ($\geq$ 2-cell) and in vitro/in vivo development rates were examined. $\pi$ Ie results were summarized as follows: in vitro maturation rate of immature mouse oocytes in vitrified-thawed group was similar to that in exposed group (67.5%) and control (66.3%), but cleavage rate of vitrified-thawed oocytes (64.9 %) and blastocyst formation rate (59.0%) were significantly different compared to those of exposed group (83.7 and 74.7%) and control (90.7 and 83.7%) (p＜0.05). However, when the blastocysts derived from immature mouse oocytes vitrified-thawed were transferred to pseudopregnant mouse, total implantation (31.3%) was slightly lower than that in control (40.8%), but live fetus formation rate (66.7%)was slightly higher than that in control (58.1%), there was not significantly different. Therefore, when the blastocyts produced in vitro were transferred into recipients, although the development in vitro of oocytes vitrified-thawed was decreased, live fetus formation rate was similar to that of control group. The present results indicate that immature mouse oocytes can be frozen successfully by vitrification with EFS40.

• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.9-11
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• 2001

현 단계에서도 임계전류밀도가 약 $100A/mm^2$로 충분히 높아 전력분야 응용이 기대되는 Bi-2223테이프에 대한 교류손실을 초전도 전력기기의 실제 상황을 고려하여 측정하였다. 중요한 평가 결과로서는 먼저 통전손실 특성은 외부 교류자장의 세기뿐만 아니라 방향에 따라서도 매우 상이하였으며, 비교적 외부자장이 큰 경우는 동저항손실 메카니즘이, 작은 경우는 그 외의 또 다른 손실 메카니즘이 지배적이었다. 또한 수평자장에 대한 자화손실 특성은 코아 모델로부터 계산된 손실과 비교적 잘 일치하였다. 따라서 자화손실은 히스테리시스 손실 메카니즘이 지배적이라 할 수 있으며, 측정된 자화손실은 저온 초전도체에서는 볼 수 없었던 약한 주파수 의존성을 보였을 뿐만 아니라 외부자장의 세기에 따라서도 주파수 의존 특성이 상이하였다.