• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.4
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• pp.633-640
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• 2004

This study was performed to investigate the cytotoxic effect of the water-extract from Chaga mushroom (Inonotus obliquus) compositions containing powdered green tea in HCT-15 human colon carcinoma, AGS human gastric carcinoma and NIH3T3 mouse normal fibroblast cells using viable cell count and MTT assay. The water-extract from Chaga mushroom compositions induced inhibitory effects on proliferation of HCT-15 and AGS cells in the MTT assay and viable cell count. However, mouse normal NIH3T3 cells were exhibited 80% survival under the same condition. Chaga mushroom compositions showed highly antiproliferative effect in human cancer cell line HCT-15 and AGS, but not in mouse normal cell line NIH3T3. These results suggest that Chaga mushroom (Inonotus obliquus) compositions containing powdered green tea are the candidate for chemoprevention in colon and gastric cancer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.421-421
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• 2008

Generally, the polymer thick-film resistors for embedded organic or hybrid substrate are patterned by screen printing so that the accuracy of resistor pattern is not good and the tolerance of resistance is too high(${\pm}$20~30%). To reform these demerits, a method using Fodel$^{(R)}$ technology, which is the patterning method using a photosensitive resin to be developable by aqueous alkali-solution as a base polymer for thick-film pastes, was recently incorporated for the patterning of thermosetting thick-film resistor paste. Alkali-solution developable photosensitive resin system has a merit that the precise patterns can be obtained by UV exposure and aqueous development, so the essential point is to get the composition similar to PSR(photo solder resist) used for PCB process. In present research, we made the photopatternable resistor pastes using 8 kinds of epoxy acrylates and a conductive carbonblack (CDX-7055 Ultra), evaluated their developing performance, and then measured the resistance after final curing. To become developable by alkali-solution, epoxy acrylate oligomers with carboxyl group were prepared. Test coupons were fabricated by patterning copper foil on FR-4 CCL board, plating Ni/Au on the patterned copper electrode, applying the resistor paste on the board, exposing the applied paste to UV through Cr mask with resistor patterns, developing the exposed paste with aqueous alkali-solution (1wt% $Na_2CO_3$), drying the patterned paste at $80^{\circ}C$ oven, and then curing it at $200^{\circ}C$ during 1 hour. As a result, some test compositions couldn't be developed according to the kind of oligomer and, in the developed compositions, the measured resistance showed different results depending on the paste compositions though they had the same amount of carbonblack.

• Preventive Nutrition and Food Science
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• v.16 no.4
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• pp.381-385
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• 2011

The degree of maturity of rice greatly affects the quality of the rice, including factors such as the integrity of grains, color, and the nutritive components. Green Rice$^{(R)}$ is rice (Oryza sativa L.) that has been harvested earlier than brown rice and appears green in color. To determine suitable harvesting time of the Jinbu variety of Green Rice$^{(R)}$ in Gyeonggido, rice samples harvested on 23, 26 and 42 days after heading (DAH) were compared on their yield, color intensity, and proximate compositions. The maximum paddy yield of Green Rice$^{(R)}$ was 61.4% at 23 DAH, which decreased to 45.4%, 5.5% at 26 and 42 DAH, respectively. Greenness was darker at 23 DAH ($-0.27{\pm}0.03$), and significantly weaker (p<0.05) at 26 DAH ($0.07{\pm}0.01$) and at 42 DAH ($5.25{\pm}0.08$). All proximate compositions, except carbohydrate, including moisture, crude fat, protein, ash and total minerals were higher in the earlier-harvested Green rice$^{(R)}$ than in brown rice, without variations among the 23 and 26 DAH Green rice$^{(R)}$. Overall, the optimum harvest time of Jinbu Green Rice$^{(R)}$ at Gyeonggido would be 23 DAH. We suggest that timely harvesting could be a potent determinant of the quality of Green Rice$^{(R)}$.

• Journal of Forest and Environmental Science
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• v.30 no.3
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• pp.285-292
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• 2014

Essential oil yields and chemical compositions from 5 populations of Chamaecyparis obtusa with several environmental factors were investigated through essential oil extracted distillation apparatus and metabolite profiling by GC-MS analysis. Among the populations, content of essential oil at Gokseong was significantly higher than other populations. To compare the several environmental factors affecting on chemical composition and essential oil yields from C. obtuse at Gokseong, the environmental factors (soil condition, temperature, humidity, and moisture content) were measured during 1 year. The essential oils at Goksung based on humidity on March, July, and November was significantly different from other months. The essential oils at Goksung based on temperature on July and August was significantly different from other months. The essential oils at Goksung based on the moisture content on September were significantly different from other months. The percentage of T-N, OM, and yield of oil at Gokseong were significantly different on from other populations. The main constituents of C. obtusa at all populations were ${\alpha}$-pinene, ${\beta}$-pinene, ${\alpha}$-terpinene, ${\gamma}$-terpinene, terpinene-4-ol, isobonyl acetate, terpinyl acetate, and cedar acetate. Specially, Essential oil compositions (%) of ${\alpha}$-terpinene and cedar acetate were higher at Gokseong than at other populations. The chemical compositions of essential oils were variable depend on populations and environmental conditions. Therefore, this study might be used as fundamental research on study for selection of high productive terpenoids and for understanding about biosynthesis of essential oils in C. obtusa.

• Atmosphere
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• v.20 no.3
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• pp.261-271
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• 2010

Carbon isotopic compositions of the YC-2 stalagmite in Yongcheon Cave were analyzed to delineate paleoclimatic variations near Korean peninsula for the past historical period. The YC-2 stalagmite is about 68 mm long and annual growth laminae are distinctively identified. Because the number of growth laminae is at least 242, the stalagmite can be estimated to be at least 241 years old. At about 15 mm from the bottom, one thick brown growth lamina is observed, and this lamina was likely to have been formed when the stalagmite ceased to grow, making the hiatus. High resolution, carbon isotope data indicate past fluctuations of East Asia monsoonal intensity (intimately related to the amount of precipitation). Based on the carbon isotope trend, the stalagmite can be divided into three stages (Stages I, II and III). The highest carbon isotopic compositions of Stage I (${\delta}^{13}C$=-3.3~0.4‰, PDB) indicate that the stalagmite grew during the Little Ice Age when cold and dry climate prevailed with less vegetation. Stage II is characterized by a transitional period from cold and dry to warm and wet climate with a increasing trend of carbon isotopic compositions (${\delta}^{13}C$=-9.6~-0.6‰) and this period indicates the weakening of the Little Ice Age climate. This decreasing trend also suggests that Little Ice Age was terminated near middle 1870's around Korean peninsula. Relatively low carbon isotopic compositions during Stage III (${\delta}^{13}C$=-11.0~-8.0‰) indicates that the climate was changed to warm and wet conditions which are similar to the present.

• Ocean and Polar Research
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• v.37 no.4
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• pp.327-332
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• 2015

Isotopic compositions of ice and meltwater play a very crucial role in paleoclimate studies based on ice cores and water resources research conducted in alpine hydrogeology. Better understanding of variations in the stable isotopic compositions of water is required since changes from ice to liquid water are gaining more attention due to recent climate change. In this work, a melting experiment was designed and conducted to investigate how the isotopic compositions of ice vary with time by heat sources, such as solar radiation. We conducted the melting experiment for 22 hours. The discharge rate rose to a maximum value after 258 minutes and gradually declined because we fixed the heat source. The isotopic compositions of meltwater increased linearly or to a second degree polynomial. The linear relationship between oxygen and hydrogen has a slope of 6.8, which is less than that of the Global Meteoric Water Line (8) and higher than a theoretical value (6.3). The deuterium excess decreased when ${\delta}D$ or ${\delta}^{18}O$ increases or vise versa since the slope of the relationship for ice-liquid exchange is less than 8. These findings and the apparatus of the melting experiments will make a helpful contribution to the studies of stable isotopes and the melting process in temperate and polar regions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.1
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• pp.79-90
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• 2018

Fish ages are critical information in fish stock assessments because they are required for age-structure models such as virtual population analysis and stochastic catch-at-age models, whose outputs include recruitment strengths, a spawning stock size (abundance or biomass), and the projection of a fish population size in future. However, most countries other than the developed countries have not identified ages of fish caught by fisheries or surveys in a consistent manner for a long time (e.g.,>20 years). Instead, data about fish body sizes (e.g., lengths) have been well available because of ease of measurement. To infer age compositions of fish in a target group using fish length data, we intended to improve the length frequency analysis (LFA), which Schnute and Fournier had introduced in 1980. Our study was different in two ways from the Schnute and Fournier's method. First we calculated not only point estimates of age compositions but also the uncertainty in those estimates. Second, we modified LFA based on the von Bertalanffy growth model (vB-based model) to allow both individual-to-individual and cohort-to-cohort variability in estimates of parameters in the vB-based model. For illustration, we used data about lengths of Korean mackerel Scomber japonicas caught by purse-seine fisheries from 2000-2016.

• Applied Biological Chemistry
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• v.40 no.2
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• pp.148-151
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• 1997

Platycodon root contains abundant pharmaceutical substances and is widely used as a food and a medicinal herb. To identify the major components of the three-year-old and the 24-year-old platycodon roots cultivated in a local farm were analyzed and compared with their chemical compositions prior to their pharmaceutical substances, which were used as the fundamental data. There were no differences in chemical composition, inorganic compositions and fatty acid compositions between the 24-year-old and three-year-old roots. Total amino acid contents were 375.8 mg% and 891.6 mg% in the 24-year-old and three-year-old platycodcon roots, respectively. Sixteen species of amino acid were identified by amino acid autolyzer except cysteine both in the 24-year-old and three-year-old roots. Linoleic acid, which was the highest fatty acid contained both in the 24-year-old and three-year-old roots, was estimated to be 48.7% and 39.1% of total fatty acids, respectively.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.847-853
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• 1997

Attempts were made to determine the compositions of Opuntia ficus-indica var. saboten for the utilization as food materials. The major components of Opuntia ficus-indica and aloe in proximate compositions were nitrogen free extract. Total mineral contents of stem, fruit and seed of Opuntia ficus-indica were 9400.8, 6151.2 and 1096.8 mg%, respectively, and their major minerals were Ca, P and Mg. The major free amino acids of fruit were tyrosine, proline and arginine, those of stem were glycine and arginine and that of seed was glutamic acid. The major amino acid of fruit was glutamic acid, those of stem were glycine and arginine and those of seed were glutmic acid and arginine. Vitamin C contents of fruit and stem were 163.8 and 71.2 mg% but not presented in seed. Vitamin A was also not presented in fruit, stem and seed. Contents of total polyphenols and flavonoids were changed by extraction solvent and temperature. Total polyphenols of fruit were higher than those of stem and seed. Total flavonoids of fruit were similar to those of stem.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.12
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• pp.955-963
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• 2006

Nucleate pool boiling heat transfer coefficients (HTCs) were measured with one nonazeotropic mixture of Propane/Isobutane and two azeotropic mixtures of HFC134a/Isobutane and Propane/HFC134a. All data were taken at the liquid pool temperature of $7^{\circ}C$ on a horizontal plain tube with heat fluxes of $10kW/m^2\;to\;80kW/m^2$ with an interval of $10kW/m^2$ in the decreasing order of heat flux. The measurements were made through electrical heating by a cartridge heater. The nonazeotropic mixture of Propane/Isobutane showed a reduction of HTCs as much as 41% from the ideal values. The azeotropic mixtures of HFC134a/Isobutane and Propane/HFC134a showed a reduction of HTCs as much as 44% from the ideal values at compositions other than azeotropic compositions. At azeotropic compositions, however, the HTCs were even higher than the ideal values due to the increase in the vapor pressure. For all mixtures, the reduction in heat transfer was greater with a larger gliding temperature difference. Stephan and $K{\ddot{o}}rner's$ and Jung et al's correlations predicted the HTCs of mixtures with a mean deviation of 11%. The largest mean deviation occurred at the azeotropic compositions of HFC134a/Isobutane and Propane/HFC134a.