• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.25 no.2
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• pp.37-43
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• 1989

The purpose of this study is to find the light intensity which induced maximum gathering rate and to observe the variation of the gathering rate both in daytime and at night by suing Rudder fish, Girella punctata(Gray). An experimental tank(360L*50W*55H cm) was set up in a dark room. An illumination system was attached to the end of one side of the tank to control horizontal light intensity. Eight artificial light sources were prepared by combination of three light bulbs(10W, 60W, 100W) and eight filters. During the experiment water depth was maintained 50cm level in the tank. The tank was marked into six longitudinal sections each being 60cm long to observe the distribution of fish. The fish were acclimatized in dark condition for 50 minutes prior to the main experiment. Upon turning on the light, the number of fish in each section was counted 60 times every 30 seconds, and the gathering rate was obtained from the average number of fish in each section. The light intensity inducing maximum gathering rate was 2.98 lux(1.90-4.40 lux) at daytime and 298.56 lux(188.44-444.96 lux) at night. The variation of the gathering rate of fish in illumination time was great and irregularly fluctuated, but did not show any definite pattern. It was somewhat difference between daytime and night.

• Applied Biological Chemistry
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• v.27
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• pp.3-17
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• 1984

Anaerobic digestion has recently attracted all over the world and Korea also shows no exception. The major benefits of anaerobic digestion are energy production, water pollution control, pathogen reduction and effective manure production. In Korea it was recognized in late sixties that there was a positive need to find alternative energy for farmers household. The main traditional energy sources in rural area were crop residues and forestry products. Therefore Office of Rural Development through its Rural Guidance Bureau disseminated about 29,000 household biogas units from 1969 to 1975 to provide cooking fuel for farmers household and to improve the mode of farmers living standards. The units were welcomed by farmers at that time. Now, however, most of them are not using due to a number of reasons associated with cold winter and some techno-economical problems (in those day, fossil fuel was quite expensive to compare with other prices and since then farmers income was quickly increased). The author studied on bag type household biogas plant to solve some technical problems of existing household biogas plants, but this also has little appeal for the farmers. From 1977 author studied on village scale biogas plant with two pilot plants. From the viewpoint of energy production, COD removal, kill rate of pathogen and fertilizer value, the results obtained from the experiments were quite promising, but the construction cost of the village scale biogas plant was too high for the farmers in Korea. To find most suitable biogas plant for farmers in Korea through the simplifying the biogas digester, the author developed batch-load biogas plant. By feeding coarse crop residues and manures, total solids concentrations of the batch-load biogas plant are about 28 percent which is much higher than continous digester of 5-8 percent. The batch-load biogas plant was welcomed by many farmers in Korea when it was reported on TV and newspapers. The plant was disseminated 154 units in 1982, 766 units in 1983 and 812 units in 1984 as a promissing project. Besides these biogas plant experiments, studies were also conducted 1) to determine gas production rate with agricultural wastes, 2) to evaluate the effect of loading rate, dilution, retention time on biogas production, 3) to project the amount of potencial energy from agricultural wastes.

• Korean Journal of Medicinal Crop Science
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• v.16 no.1
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• pp.1-8
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• 2008

Immune activities of Opuntia ficus indica L. Miller were investigated through aqueous extracts associated with ultrasonification process at $60^{\circ}C$, and showed the highest promotion of human B and T cell growth, up to 52% and 41%, respectively, compared to the control. The secretion of TNF-${\alpha}$ and IL-60 was also enhanced by the addition $(0.5mg/m{\ell})$ of the extracts, up to 48%. NK cell activation was significantly improved up to 1.3 times higher than the case of adding other extracts. It was also found that extracts from O. ficus indica could yield higher nitric oxide production from macrophage than Lipopolysaccaharides (LPS). It can be concluded that, in general, the extracts treated with ultrasonification has higher Immune acitivities than others, possibly by higher yielding immune-modulatory than conventional extraction process. The optimum condition for the extraction of O. ficus-indicais water extraction associated with ultrasonification.

• Applied Biological Chemistry
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• v.32 no.4
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• pp.327-331
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• 1989

In this study the Theological properties between C1-treated soft wheat flour and untreated soft wheat flour was determined. Chlorine treatment lowered pH of the flour in a linear fashion. Water absorption and dough stability was high in proportion to the increase of treatment level but mechanical tolerance index was reduced by each increment of chlorine. The valorimeter value did not exhibit reproducible trend on treatment of chlorine. In general, resistance(BU), resistance to extension and maximum viscosity(BU) were highest in control group; lowest in 1 oz./cwt. flour and tended to rise in 2 oz./cwt. flour when it fermented in chamber for 90 min and 135 min. The maximum viscosity was highest (1,160BU) in 4 oz./cwt. flour and temperature at maximum viscosity tended to rise gradually in proportion to the increase of treated level.

• Journal of Acupuncture Research
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• v.28 no.1
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• pp.1-14
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• 2011

목적 : 인진약침이 고지방식이로 유발된 비만 ICR mice에서 비만 및 동반 대사이상에 미치는 효과와 그 기전을 연구하고자 한다. 방법 : 인진약침의 비만 예방효과를 검증하기 위하여, 4주간 고지방식이를 급여하면서 150mg/kg 또는 300mg/kg의 인진약침을 양측 비수($BL_{20}$)에 교대로 매일 피하에 시술하였다. 또한 인진약침의 비만 치료효과를 검증하기 위하여, 4주간 고지방식이를 급여한 비만 ICR mice에 추가 4주간 고지방식이를 유지하면서 300 mg/kg 인진약침액과 vehicle control로써 등량의 distilled water를 양측 비수($BL_{20}$)에 교대로 매일 피하에 약침시술하였다. 인진약침의 항비만효과와 기전을 알아보기 위해, 체중, blood glucose, insulin, total cholesterol, triglyceride, non-esterified fatty acid (NEFA), AST, ALT levels 등 대사지표를 측정하고 부고환조직의 조직학적 관찰을 시행하였으며, AMPK activation과 adipocyte differentiation, fatty acid ${\beta}$-oxidation 및 thermogenesis와 관련된 gene expressions을 평가하였다. 결과 : 인진약침의 치료를 통하여 고지방식이 급여로 인한 체중의 증가가 억제되었을 뿐만 아니라, 비만 ICR mice의 체중을 감소시켰으며, glucose 및 lipid homeostasis를 개선시켰으며 지방조직의 증식을 억제하였다. AMPK의 phosphorylation과 CPT-1 및 UCP2의 발현을 증가시켰으며, PPAR-${\gamma}$, C/EBP${\alpha}$, aP2, LPL,FAS, SCD-1의 발현을 억제하였다. 결론 : 인진약침은 고지방식이 유도 동물모델에서 비만 및 동반 대사이상을 개선시키는 효과가 있으며, 이는 식이억제에 의한 2차적 효과라기 보다는 energy expenditure를 증가시키고, pre-adipocyte differentiation 및 proliferation을 억제하며, lipogenesis를 억제하고 lipolysis를 증가시키는 효과에 의한 것으로 사료된다.

• Magazine of the Korea Concrete Institute
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• v.7 no.6
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• pp.176-185
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• 1995

The heat generation of hydration of cement causes the internal temperature rise and volum& change at early age, particularly in massive concrete structures. As the results of the temperature rise and external restraint conditions, the thermal stress may induce cracks in concrete. Therefore, various techniques of the thermal stress control of the mass concrete have been wid'dy used. One of them is pipecooling which reduces the temperature of concrete with flowing water. The objective of this paper' is to develop a finite element program which is capable of simulating the temperature history considering pipe-cooling effect. The numerical results in this study are in good agreement with experimental data measured in the footing(l1 x22m). Therefore, this study may provide available method to predict the hydration temperature of concrete with pip:-cooling.

• Journal of the Korea Concrete Institute
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• v.16 no.3 s.81
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• pp.391-396
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• 2004

Plastic shrinkage crack occurs at the exposed surfaces of freshly placed concrete due to consolidation of the concrete mass and rapid evaporation of water from the surface. This so-called shrinkage crack is a major concern for concrete, especially for flat structures such as pavements, slabs for industrial factories and retaining walls. This study has been performed to obtain the plastic shrinkage and the permeability of hydrophilic poly vinyl alcohol(PVA) fiber reinforced mortar and concrete. Test results indicated that PVA fiber reinforced cement composite showed an ability to reduce the total crack area and the maximum crack width (as compared to plain and polypropylene fiber reinforced concrete). Also, according to the permeability test result, it was found that PVA fiber reinforced cement composite was more reducing than polypropylene fiber reinforced cement composite.

• The Korean Journal of Ecology
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• v.27 no.1
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• pp.35-41
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• 2004

Phragmites australis is the dominant and constructive species among plant communities in the wetlands of the downstream of Yellow River, China. Its morphological characters were high variable in different habitats. Studies on Morphological and RAPD variation of 15 P. australis populations from this region showed that soil salinity was the dominant ecological factor that affected the morphological characters of P. australis. The basal diameter, height, leaf length, leaf width, internode length, internode accounts, panicle length were negatively related to salinity. 194 loci were amplified by RAPD, of which 9 loci was highly negative-related to salinity, and showed a tendency to prefer the habitats with fresh water. 4 loci were positively related to the salinity, and showed a tendency to prefer the salinized habitats. Most loci were neutral to salinity. The morphological and genetic characters of BZH were special, and the speciality should not be determined by salinity. The morphological characters were affected by genetic information and environment. The morphological characters should change gradually and continuously along environmental gradient under plasticity, but should changed continuously or not in genetic control. The relevancies among quantitive characters, ecological factors and genetic variation in natural populations still will still be a focus and difficulty of ecological genetics of P. australis in the future.

• Journal of Environmental Science International
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• v.6 no.2
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• pp.125-131
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• 1997

The mechanism of stomatal closing in response to $O_2$ was indirectly investigated by using $H_2O_2$ which is the intermediate product of $O_2$ metabolites. Stomata in epidermal strips close in response to $H_2O_2$. The effect of $H_2O_2$ on stomatal closing was dependent on the concentration of $H_2O_2$. 10 ppm $H_2O_2$ showed a clear effect on stomatal closing and 1000 ppm $H_2O_2$ induced complete stomatal closing after the treatment of 3 hours. Stomatal closing by $H_2O_2$ in intact leaf was also observed by measuring the diffusion resistance with porometer. It was found that the stomatal closing by $H_2O_2$ was not mediated by $Ca^{2+}$, and that was a different result observed in stomatal closing by water stress. Reversely, $Ca^{2+}$ showed a great inhibition on stomatal closing. The leakage of K+ in epidermal strips was doubled in response to $H_2O_2$ when it was campared to the control. 10 ppm $H_2O_2$ decreased photosynthetic activity. Fv/Fm representing the activity of Photosystem II was reduced about 4 % in 10 ppm $H_2O_2$ and 8 % in 100 ppm $H_2O_2$ In the treatment of 1.5 hour. However, stomatal closing by 10 ppm $H_2O_2$ was reduced about 56 %. According1y, it can be suggested that stomatal closing by $H_2O_2$ is related with the decrease of photosynthetic activity, but it was chiefly induced by the change of the membrane permeability. Key words Commelina communis, stomatal closing, $H_2O_2$, $Ca^{2+}$, photosynthesis.

• Journal of Environmental Science International
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• v.20 no.5
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• pp.555-564
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• 2011

This study examines the potential restoration of abandoned channels of the Mangyeong River in South Korea. To analyze the morphological changes and equilibrium conditions, a flow duration analysis was performed to obtain the discharge of 255 m3/s with a recurrence interval of 1.5 year. It is a gravel-bed stream with a median bed diameter of 36 mm. The reach-averaged results using HEC-RAS showed that the top width is 244 m, the mean flow depth is 1.11 m, the width/depth ratio is very high at 277, the channel velocity is 1.18 m/s, and the Froude number is also high at 0.42. The hydraulic parameters vary in the vicinity of the three sills which control the bed elevation. The total sediment load is 6,500 tons per day and the equivalent sediment concentration is 240 mg/l. The Engelund-Hansen method was closer to the field measurements than any other method. The bed material coarser than 33 mm will not move. The methods of Julien-Wargadalam and Lacey gave an equilibrium channel width of 83 m and 77 m respectively, which demonstrates that the Mangyeong River is currently very wide and shallow. The planform geometry for the Mangyeong River is definitely straight with a sinuosity as low as 1.03. The thalweg and mean bed elevation profiles were analyzed using field measurements in 1976, 1993 and 2009. The measured profiles indicated that the channel has degraded about 2 m since 1976. The coarse gravel material and large width-depth ratio increase the stability of the bed material in this reach.