• Applied Microscopy
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• v.29 no.1
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• pp.11-23
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• 1999

Ultrastructure of the ependymal cells of X-irradiated rats on their head were studied. Rats weighing $200\sim250gm$ were X-irradiated on their head and neck areas. Total exposures were 3,000 rads or 6,000 rads depending on experimental groups. And irradiated rats were sacrificed on 6 hours, 2 days and 6 days following the radiation exposures. Animals were perfused through the heart with 1% glutaraldehyde-1% paraformaldehyde solution, under ether-anesthesia. The tissues from the wall of lateral ventricles were fixed in the 2% osmium tetroxide solution. The results observed with electron microscope were as follow: 1. In 6 hours group, many ependymal cells were swelled, luminal portions of cytoplasms of some cells protruded into the ventricular lumen, and many cilia were lost or irregularly altered. 2. In 2 days group, ependymal cells were swelled more severely and subependymal edema were pronounced. 3. Protruded cytoplasm contained usually basal bodies of cilia, groups of mitochondria, endoplasmic reticula , etc. 4. Following X-irradiations, some protruded masses contained neural elements including the axon terminals with dense core vesicles. Axons and axon terminals were also found in the enlarged intercellular spaces among ependymal cells. From the above results, the heavy irradiation on the head area of the rat induced alteration of the ependymal cells lining the lateral ventricle. Hence the ependymal functions of selective barrier, protective barrier, and metabolic barrier could be altered following X-irradiation on the head.

• Journal of the Korean Society of Propulsion Engineers
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• v.7 no.1
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• pp.28-39
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• 2003

Effects of the orifice internal flow such as cavitation and hydraulic flip on transverse injection into subsonic crossflows have been studied. The liquid column breakup length and the liquid column trajectory were measured by changing the orifice diameter (d), the orifice length/orifice diameter (L/d), the injection pressure and the shapes (sharp and round) of orifice entrance, and were compared with previous results. It is found that cavitation bubbles, which occur inside the sharp-edged orifice, make the liquid jet very turbulent and especially in the orifices with L/d ＝ 5 hydraulic flip appear as cavitation bubbles are emitted from the orifice. The breakup length is shorter as cavitation bubbles grows and hydraulic flip appears. However, the liquid column trajectories normalized by the effective diameter and the effective momentum ratio have a similar tendency irrespective of cavitation and hydraulic flip.

• Journal of the Korean Wood Science and Technology
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• v.23 no.4
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• pp.27-32
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• 1995

To understand whether ligninolytic enzyme catalyze polymerization or depolymerization of the high molecular weight (HMW) lignin, the action of laccase and Mn-peroxidase (MnP) towards commercial ligninsulfonates (LS) was examined in various conditions of pH and cosubstrates. Polymerization occurred when LS was incubated with laccase at pH 6.0. In contrast, the high molecular weight portions were significant1y reduced at pH 4.5, especially when glucose was added. When LS was treated with MnP at pH 4.5, compounds of low molecular weight were produced. In particular, when cellobiose was added to Mn-P reaction mixture, the breakdown of LS was observed. In conclusion, degradation of LS by laccase and MnP occurred primarily at pH 4.5 where-as polymerization of LS was dominant at pH 6.0. Color index, however, was not greatly changed in the degradation mixtures of LS.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.419-419
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• 2018

기후변화로 인한 홍수피해의 빈도와 규모가 증가함에 따라 미래 홍수취약성은 갈수록 증가할 것으로 전망된다. 이를 대비하기 위해서는 지역별 기후변화를 고려한 홍수취약성 평가를 통해 적절한 적응 정책을 수립하여야 한다. 본 연구에서는 지역별 홍수취약성을 평가하기 위해 홍수취약성지수(Flood Vulnerability Index, FVI)를 새롭게 선정하였다. FVI는 3가지 구성요소의 결합으로 산정되며, 피해의 원인이 되는 압력지수(Pressure Index), 물리적 피해 현황을 나타내는 현상지수(State Index), 대응할 수 있는 능력인 대책지수(Response Index)의 함수로 나타낸다. 압력지수는 기후, 유역, 사회특성에 따라 세부지표를 구분하였고, 현상지수는 홍수피해 비율, 대책지수는 기술 및 사회적 특성을 기준으로 하였다. 따라서, 압력지수 및 현상지수가 클수록 홍수피해에 취약함을 나타내고, 대책지수가 클수록 취약성이 저감되게 된다. 연구 대상 지역은 최근 집중호우로 인해 많은 홍수피해가 발생한 금강유역을 선정하였고, 과거 홍수 피해액 자료를 사용하여 선정된 지수의 적용성을 검토하였다. 또한, 기후변화를 고려하기 위해 27개의 GCMs (Global Climate Models) 중 홍수를 가장 잘 설명하는 5개의 대표시나리오와 2개의 배출시나리오(RCP4.5, RCP8.5)를 사용하였으며, 과거(2010년대) 및 2030년대, 2050년대, 2080년대의 홍수취약성지수를 산정하여 결과를 분석하였다. Spearmans's rank correlation coefficient를 사용하여 과거 10년간 실제 홍수 피해액의 평균값과 FVI를 비교한 결과 선정된 지수가 홍수피해를 적절히 설명하는 것으로 나타났다. 대표시나리오를 사용한 미래 홍수취약성 분석 결과, 용담댐 유역에서 홍수취약성이 증가하는 것으로 나타났으며 지역별 상대적 취약성전망 결과는 대부분 과거와 비슷하였다.

• Horticultural Science & Technology
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• v.17 no.6
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• pp.758-760
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• 1999

This experiment was carried out to investigate the effect of pretreatments and holding solutions on quality and vase life of cut 'Saphir' rose (Rosa hybrida L.). Pulsing with aluminum sulfate or NaOCl prolonged vase life held in HQS+sucrose+ethionine. Solution absorption held in distilled water were more increased than held in HQS+sucrose+ethionine. Holding solution with 8-hydroxyquinoline sulfate (HQS)+sucrose+ethionine increased fresh weight compared with distilled water except pulsing with STS+sucrose. Pulsing with aluminium sulfate delayed bent-neck held in HQS+sucrose+ethionine. Flower diameter and dry weight of petal held in HQS+sucrose+ethionine were more increased than held in distilled water except pulsing with STS+sucrose. There were no significance in Hunter color value 'L' and value 'a', but value 'b' was decreased held in distilled water.

• Korean Journal of Food Science and Technology
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• v.20 no.4
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• pp.488-492
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• 1988

The physicochemical properties of viscosity, color, acidity and volume of anchovy extract were measured for their changes during extraction with alkali solution and/or proteolytic enzymes. The dried anchovies were ground in 0.3N NaOH solution followed by hydrolysis with neutral or alkaline protease and centrifuged to obtain anchovy extract. The results showed that the volume of supernatant after centrifugation increased from 70% of water only extraction to 89% by combined alkali-enzyme treatment. Titratable acidity of the extract showed a tendency of a little increase while viscosiy decreased with prolonged enzymic hydrolysis. Changes in Hunter value of 'L', 'a', 'b' showed that the extract became darker and less yellowish as protease treatment prolonged.

• Korean Journal of Organic Agriculture
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• v.7 no.2
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• pp.163-167
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• 1999

To study the effects of chemical and organic fertilizer within the contents of essential elements in the lettuce, in the absence or presence of wood extraction, an experiment was conducted for a period of 10 weeks. The results obtained from the experiment are summarized as follows: 1. The iron contents in the lettuce grown in the chemical fertilized group, were different from those in the organic fertilized group, when the wood extraction was treated. The iron contents in the lettuce increased, due to the wood vinegar treatments, but the modes and degrees were not consistent the various kinds of lettuce. 2. Calcium contents in the lettuce were also increased by wood vinegar treatments, but the modes and degrees were not consistent with the various kinds of lettuce. On the other hand, the Calcium contents in the lettuce grown in the organic fertilized group were reduced by the wood vinegar treatments. 3. The mineral contents within other elements(Manganese, Copper, Zinc) in lettuce, is not variable according to the treatments, or the species of the lettuce.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.9
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• pp.1288-1293
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• 2012

Yacon (Smallanthus sonchifolius) contains high amounts of fructooligosaccharides and has been known to promote health of the intestinal tract and to have anti-oxidative and anti-cancer activities. Yacon concentrates were added to make five different pan breads, each with the addition 0% (YE 0), 25% (YE 25), 50% (YE 50), 75% (YE 75), and 100% (YE 100) of yacon concentrates instead of sugar. The higher the yacon concentration in the dough, the more time was needed for the dough to rise. Higher yacon concentration also affected the color of the bread by lowering the L-value and raising the a and b values. The hardness and chewiness of the bread significantly decreased with increasing yacon concentration, while cohesiveness increased. In the bread sensory evaluation, the intensity of crust color, crumb color, yacon flavor, sweetness, yacon taste, moistness, and residual mouth feel were increased with increasing yacon concentrates, while the uniformity of crumb pores slightly decreased. The consumer acceptance of taste, flavor, texture, and overall acceptance were increased with increasing yacon concentrations. As a conclusion, the substitution of yacon concentrates for sugar improved bread quality and increased consumer acceptance.

• Microbiology and Biotechnology Letters
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• v.20 no.3
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• pp.316-323
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• 1992

Studies on the changes in rheological properties, molecular weight distribution and dextran yield after being reacted in lO%(w/w) sucrose concentration were performed with crude dextransucrase produced from Leuconostoc mesenteroides isolated from Sikhae. The reaction rate of dextran formation was monitored by sugar analysis with HPLC and by the changes in apparent viscosity. According to the periodate oxidation test, the dextran produced in this experiment was estimated to have 89% $\alpha$-(1->6) main linkages and 11% $\alpha$-(1->) side linkages. The rheological properties of the dextran solution formed changed with reaction time, and it was related to the changes in molecular weight distribution of dextran as determined by GPC analysis. As the reaction proceeded, the rheological behavior changed from Newtonian to non-Newtonian, showing Binghampseudoplastic and thixothropic flow behavior. The apparent viscosity of dextran formed solution increased with increasing reaction time, reached a maximum value of 2680 cP ($\gamma$=$33.75s^{-1}$, $25^{\circ}C$) by enzyme reaction for 8 hours, and then decreased. The temperature dependency of dextran formed solutions was well expressed by the Arrhenius equation and the activation energy reached a maximum value of 1.69 kcal/mole by enzyme reaction for 8 hours.

• Food Science and Preservation
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• v.14 no.2
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• pp.154-159
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• 2007

In efforts to use pine needle extract as a substitute for sugar, fermented pine needle extract syrup was added to the wheat flour nea in the manufacture of white bread The extract was added to levels of 8.3%, 11% and 18% of total weight based on the Brix degree of the dough The cohesion of each dough was checked, and the physical properties and storage stabilities of the baked breads were analyzed during storage at mom temperature. Analysis of the cohesion of each dough by farinogram showed that dough with pine needle extract was better than dough with sugar, in terms of both stability and durability of mixing. The pH of dough with syrup was steady during storage at pH 5.4 5.8, which is favorable for yeast activity. The dough with syrup also showed low firmness and good extensibility, both of which would favorably affect gas retention on fermentation. Increases in syrup addition resulted in higher product volumes. Bread with syrup was slow to increase in hardness during storage, suggesting that higher syrup concentrations inhibited development of staleness. The addition of syrup also inhibited the growth of aerobic bacteria and mold on the bread surface. The addition of syn did not cause any negative effect. The use of pine none extract syrup may thus contribute to improvements the physical properties, the storage stability, and the hygienic quality of bread.