• Journal of Advanced Marine Engineering and Technology
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• v.37 no.1
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• pp.1-8
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• 2013

The water-in-fuel droplets were applied to investigate the effect of mixing ratio between water and decane, ambient temperature, droplet size and spacing between droplets on ignition and micro-explosion in a heated chamber with high temperature. The ignition temperature of droplet was found lower as the droplet size was increased and the contents of water was decreased. The life time of droplet, however, decreases as the contents of water increases due to the micro-explosion. The occurrence of micro-explosion also increases as the size of droplets and the ambient temperature increase. The flame spread speed gets faster as the contents of water and the number of suspender decreases.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.129-133
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• 1999

Excessive soil water at vegetative growth stages during the rainy season induces yield losses in soybeans. Our objectives were to obtain basic information about the cultivar differences and to understand the stress-tolerance process for due to excessive soil water. Previous experiments revealed soybean genotypic differences in tolerance to excessive soil water. A field experiment was conducted at the Research Farm of Korea University near Seoul on 21 May 1998. Soybean[Glycine max (L.) Merrill] cultivars, 'Hannamkong' (sensitive) and 'Taekwan-gkong'(tolerant) were planted in vinyl-lined plots(1.2 x 4.2 x 0.3 m deep) and control plots. Drip irrigation began at VI growth stage to submerge the soil surface. Three weeks of excessive soil water treatment reduced all growth parameters measured to soybean plants. Excessive soil water stress resulted in decreases of N, P, K, Ca, Mg and Cu, and increases of Fe and Mn contents in soybean leaves. The stress index of tolerant cultivars under excessive soil water showed no large difference in soybean growth characteristics measured at three growth stages. However, K, Ca, Mg, Fe and Mn contents in soybean leaves appeared to differ between sensitive and tolerant cultivars. From the above results, stress and tolerance indices are proposed for a method to test cultivar differences in plant responses within a species under adverse growth environments.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.69-72
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• 2008

The local water contents and water transfer characteristics in the PEMFC system were investigated by numerical simulations and experiments. The performance of a lab-scale PEMFC is measured for fully humidified gases conditions and non-humidified ones. In order to observe the local water contents and water transfer characteristics inside PEMFC, the numerical simulation using CFD module on STAR-CD(es-pemfc) were conducted. The results show that the water content was increased as increasing current density, whereas it was decreased in high current density region. Then there was close correlation between high water content and internal temperature inside of MEA, and high current density was observed when internal temperature was dramatically increased.

• Journal of the Korean Magnetic Resonance Society
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• v.6 no.1
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• pp.1-11
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• 2002

Physical properties of PVB [Poly(vinyl butyral)] polymer are strongly correlated with water contents in the polymer. Thus dynamics of PVB containing 10~50(w/w) ％ of water were studied by $^{13}$ C CP/MAS/DD over the temperature range 293K -348K. From the Peak area, line width, chemical shift, and relaxation times ( $T_{1}$ $T_{1p}$) measured at 9.4 T, it was deduced that water facilitates molecular dynamics of the PVB molecules overall including conformational exchange of the racemic and meso butyaldehyde rings in the PVB. However, the influence of water was not linear to the amount of water in the PVB samples. It is suggested that water up to 30 w/w ％ of the sample is closely bound to the PVB polymer and water relatively free from the PVB polymer starts to appear when water is added more than 30 w/w ％.％.

• The Korean Journal of Food And Nutrition
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• v.33 no.4
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• pp.390-398
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• 2020

The purpose of this study was to determine the contents of water-soluble vitamins B₁ (thiamine), B₂ (riboflavin), B₃ (niacin) and B₁₂ (cyanocobalamin) in seafood-based dishes by using the high-performance liquid chromatography with the ultra violet and fluorescence detector. The vitamin B₁, B₂, B₃ and B₁₂ contents were analyzed in 29 seafood-based dishes. The method validation was performed on the method to determine the linearity, accuracy, limits of quantification, limits of detection and precision for vitamin B₁, B₂, B₃ and B₁₂. An excellent linearity range (R²=0.999~1.000) in the calibration curve for the water-soluble vitamins was observed. All analytical methods for the water-soluble vitamins showed the acceptable accuracy (89.4~119.7% recovery) and the precision (0.6~4.8% repeatability and 1.0~4.2% reproducibility). The highest content of vitamin B₁ was 2.646 mg/100 g in the kkongchi-jorim, and the highest contents of vitamin B₂, B₃ and B₁₂ were 0.370 mg/100 g, 10.971 mg/100 g, and 17.193 ㎍/100 g, respectively, in the kkongchi-gui. Our results provide reliable data on the contents of the water-soluble vitamins of seafood-based dishes in Korea.

• Korean Journal of Environmental Agriculture
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• v.16 no.2
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• pp.187-192
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• 1997

We carried out a survey on tributary streams in some agricultural areas along Nakdong River to evaluate the effects of agricultural practices on pollution of stream water and groundwater. General properties, nutrient materials and heavy metals in water samples were measured. General physicochemical properties of tributary stream waters were at levels favorable for agricultural water. Heavy metals, except Zn, were mostly not detected. Total-N contents were much higher than the criteria of agricultural water, and nitrate-N accounts for more than a half of total-N. Phosphorus contents were higher than the lower level of P for algae growth and the contents were high especially in summer. In ground waters which are used for irrigation, P were mostly at same levels as those in streams, and nitrate contents were higher than 10mg/L in some samples. In these results only those N and P contents in stream and ground waters higher than pollution criteria are problematic and they are traceable to agricultural nonpoint sources-fertilizers, livestock farms and sewage. Further researches are needed to evaluate contributions of each nonpoint source on stream water pollutions.

• Korean Journal of Pharmacognosy
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• v.41 no.2
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• pp.130-135
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• 2010

This study was performed to the activity of antioxidant and anti-diabetic from Zanthoxylum schnifolium fruit. The Zanthoxylum schnifolium fruits were extracted with water, 100% methanol, 100% ethanol, 70% methanol and 70% ethanol. The activities of each extracts were measured by antioxidant tests, such as total phenolic contents, total flavonoid contents, hydroxyl radical activity, DPPH radical scavenging activity, reducing power and $\alpha$-glucosidase inhibition activity assay. The water extract represented the highest activity in the antioxidants properties in vitro, including hydroxyl radical activity, DPPH radical scavenging activity, reducing power. Furthermore, water extract also showed significantly high total phenolic contents but the 100% methanol extract showed high total flavonoid contents estimated as $196.48{\mu}g/mg$. The $IC_{50}$ values for $\alpha$-glucosidase inhibition activity of the 100% ethanol and 100% methanol extracts were $275.66{\mu}g/mg$ and $261.44{\mu}g/mg$. Our results indicated that the Zanthoxylum schnifolium fruit expected to be useful as antioxidants.

• Korean Journal of Environment and Ecology
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• v.20 no.4
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• pp.425-435
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• 2006

The objectives of this research were to investigate the drought resistance as well as the growth of Wisteria floribunda seedlings with the soil water conditions. The seedlings for the research were grown in pots with strict water content control on a frame located outdoors. During the experiments, the soil water contents were adjusted to 5, 10, 20, 30, 40, 50, 60, and 70%. In addition, the effects of Rhizobium inoculation on the growth of seedlings were investigated. The experimental results are summarized as follows: 1. The seedlings in the pots with 5% soil water content withered to death due to the water stress. Withering or any distinct growth was not observed from the seedlings in the 10% soil water content. It can be inferred from these results that about 5% of soil water content is the wilting point of W. floribunda seedlings and about 10% is the critical soil water content of its growth in this experiment soils. Therefore, it seems that W. floribunda possesses a good drought resistance. 2. From the analyses of the main growth parameters such as stem elongation, diameter growth, leaf area growth and total dry weight, it was found that the seedling growth can be improved with increasing soil water contents. The relation between each growth parameter(Y) and the soil water contents(W) was well described by a quadratic equation, $Y=a+bW+cW^2$. 3. In soil water contents higher than 20%, the seedling growth(Y) was remarkable along with-its extended growing period, and related to the growing period(D) by a quadratic equation, $Y=a+bD+cD^2$. 4. The artificial inoculation of Rhizobiun promoted the growth of Wisteria floribunda seedlings. 5. Rhizobium was found to be more readily inoculated and to form more root nodules compared to seedlings grown in higher soil water contents.

• Journal of Society of Preventive Korean Medicine
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• v.17 no.3
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• pp.177-185
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• 2013

Objective : Eucommiae Cortex is bark of Eucommia ulmoides Oliver, a deciduous tree native to China. Today, teas or herbal drugs made from E. ulmoides leaves are widely consumed as a healthy food especially in Eastern Asia including Japan, China and Korea. This study was aimed to verify the extraction efficiency of bioactive compounds from Eucommiae Cortex depending on characteristics of decoction water. Method : Six types of decoction water with various origin were prepared and the contents of minerals in water were analyzed by ICP-AES and ICP-MS. The contents of extracted bioactive compounds were analyzed by HPLC and the relationship between mineral contents and extracted bioactive compounds in the decoction water were analysed by multiple factor analysis. The decoction waters could be classified in three groups by hierarchical cluster analysis. Result : Extracted amounts of compounds in Eucommiae Cortex showed a positive relationship with Na, Si, K concentration in decoction water, while a negative relationship with Ca, Mg concentration. Conclusion : The study proved that the minerals in water influenced the extraction efficiency of bioactive compounds from Eucommiae Cortex.

• Ocean and Polar Research
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• v.25 no.1
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• pp.41-52
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• 2003

Sediment trap samples were collected to find out characteristic behaviors of metals in the settling particles by using time-series sediment traps at 678m and 1678m water depths in the Bransfield Strait from December 27th, 1999 to December 26th, 2000. Total mass fluxes at the intermediate water depth (678m water depth) were high in the austral summer and low in the austral winter, whereas at the deep water depth (1678m water depth) they showed high values in both the summer and winter. Total mass fluxes were generally higher in the deep water depth than in the intermediate water depth, which indicates that a substantial amount of sediments are laterally transported by strong currents into the deep basin from the shallow water depths. Aluminium contents also showed large seasonal variations with high values in the winter and low values in the summer. On the contrary, organic carbon contents were high in the summer and low in the winter. Al contents were negatively correlated with organic carbon contents, which may be ascribed that detrital particles are diluted by organic matter produced by phytoplankton in the surface waters. Metals measured in this study exhibited three characteristic behaviors; 1) a positive correlation with Al-Ti, Fe, Mn, V, Co, and Ba, 2) a negative correlation with Al-Cd and Zn, 3) no relationship with Al-Sr, Cu, Cr, Ni. Terrestrial materials may act as a major source fer metals that are positively correlated with Al, and organic matter may be a major source for metals that are negatively correlated with Al. Enrichment factor (EF) of Fe, Mn, Ba, Vi Co, Sr, Cr, and Ni ranged from 0.5 to 1.5, whereas EF of Zn, Cu, and Cd showed much higher values than 1.