• Economic and Environmental Geology
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• v.34 no.1
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• pp.25-38
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• 2001

Contrasts in the style of the gold-silver mineralization in geologic and tectonic settings in Korea, together with radiometric age data, reflect the genetically different nature of hydrothermal activities, coinciding with the emplacement age and depth of Mesozoic magmatic activities. It represents a clear distinction between the plutonic settings of the Jurassic Daebo orogeny and the subvolcanic environments of the Cretaceous Bulgugsa igneous activities. During the Daebo igneous activities (about 200-130 Ma) coincident with orogenic time, gold mineralization took place between 197 and 127 Ma. The Jurassic deposits commonly show several characteristics: prominent association with pegmatites, low Ag/Au ratios in the ore-concentrating parts, massive vein morphology and a distinctively simple mineralogy including Fe-rich sphalerite, galena, chalcopyrite, Au-rich eIectrum. pyrrhotite and/or pyrite. During the Bulgugsa igneous activities (120-60 Ma), the precious-metal deposits are generally characterized by such features as complex vein morphology, medium to high AgiAu ratios in the ore concentrates, and abundance of ore minerals including base-metal sulfides, Ag sulfides, native silver, Ag sulfosalts and Ag tellurides. Vein morphology, mineralogical, fluid inclusion and stable isotope results indicate the diverse genetic natures of hydrothermal systems. The Jurassic Au-dominant deposits were formed at the relatively high temperature (about 300 to 450$^{\circ}$C) and deep-crustal level (>3.0 kb) from the hydrothermal fluids containing more amounts of magmatic waters (3180; 5-10 %0). It can be explained by the dominant ore-depositing mechanisms as CO2 boiling and sulfidation, suggestive of hypo/mesothermal environments. In contrast, mineralization of the Cretaceous Au-Ag type (108-71 Ma) and Agdominant type (98-71 Ma) occurred at relatively low temperature (about 200 to 350$^{\circ}$C) and shallow-crustal level «1.0 kb) from the ore-fonning fluids containing more amounts of less-evolved meteoric waters (15180; -10-5%0). These characteristics of the Cretaceous precious-metal deposits can be attributed to the complexities in the ore-precipitating mechanisms (mixing, boiling, cooling), suggestive of epilmesothermal environments. Therefore, the differences of the emplacement depth between the Daebo and the Bulgugsa igneous activities directly influence the unique temporal and spatial association of the deposit type.

• Horticultural Science & Technology
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• v.30 no.5
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• pp.477-483
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• 2012

This study was carried out to investigate the influence of copper concentrations in fertilizer solution on the growth of and nutrient uptake by domestically bred strawberries. The characterization of toxicity symptoms as well as tissue analyses based on dry weight of above ground tissue were also conducted to determine the threshold levels in plants when toxicity developed in copper. The dry weights of the above ground tissue were not significantly different among the treatments of 0.25 mM to 1.0 mM in 'Keumhyang' and 'Maehyang' strawberries and that of 0.25 mM to 3.0 mM in 'Seolhyang' strawberry. This indicates that the 'Seolhyang' strawberry is more tolerant to copper toxicity than 'Keumhyang' or 'Maehyang' strawberries. Application of copper at high concentrations resulted in severe toxicity such as death of extensive areas of leaves. The lower leaves became yellow and die rapidly as the symptoms spread up the plants. The leaf blades and petioles died back to the crown and hang on by mechanical attachment. Symptoms of copper toxicity in lower leaves developed as browning on leaf margins and in patches between leaf veins that became necrotic. The elevation of copper concentrations in fertilizer solution did not influence the tissue phosphorus, potassium, calcium, and magnesium contents based on the dry weight of the above ground tissue. The tissue copper contents increased lineally as the copper concentrations in fertilizer solution were elevated. But the tissue iron, manganese and boron contents were not influenced by the concentrations. When the concentration of copper at which growth of a plant is retarded by 10% is regarded as threshold level, the copper contents based on dry weight of above ground plant tissue should be lower than 71.4, 57.9 and 74.8 $mg{\cdot}kg^{-1}$ in 'Keumhyang', 'Maehyang' and 'Seolhyang' strawberries, respectively. The symptom characterization and established threshold level in copper toxicity would help growers to prevent the reduction of crop growth and yield in 'Seolhyang' strawberry cultivation.

• Food Science of Animal Resources
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• v.26 no.1
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• pp.9-14
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• 2006

The aim of this study was to determine the chemical traits of duck meats with different rearing periods(45 70 days). The content of protein was 21.3 and 19.61% in the breast and leg at 70 days post hatched, respectively. Group at 70 days showed high protein composition than those of 45 days group. The content of fat was slightly increased with the rearing periods. The composition of Ca, mineral compound, was not showed the difference between leg and breast meat. However, it was increased with the rearing periods. The composition of Fe was not significantly different in the breast meat. However, there was a significant increase in the leg (p<0.05). It was compared 14.6 ppm at 45 days group to 27.5 ppm at 70 days group. The content of methionine was significantly increased in the breasts due to the increasing rearing periods (p<0.05), but not in leg meat. There was no significant difference between parts, but glutamic acid content was significantly decreased along with the increasing rearing periods (p<0.05). The content of collagen at 70 days(0.77 g/100 g) was higher than those of 45 days(0.65 g/100 g). It was affected by the rearing periods In the wing-removed skit, it was 0.15 g increases at 70 rearing period group. The cholesterol content was significantly increased in the leg but not in the breast. With the rearing periods, it was significantly increased in the leg (p<0.05).

• Korean Journal of Agricultural and Forest Meteorology
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• v.3 no.3
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• pp.135-142
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• 2001

This study attempts to categorizes the factors of forest fire occurrences based on regional meteorologic data and general forest no characteristics of 18 cities and guns in Kangwon province. lo accomplish this goal, some statistical analyses such as analysis of variance, correspondence analysis and multidimensional scaling were adopted. To reveal the forest fires pattern of study region, a categorization process was conducted by employing the quantification approach which modified and quantified the metric-data of fire occurrence dates. Also, The fire occurrence similarity was compared by using multidimensional scaling for each study region. The major results are summarized as follows: It was found that the meteorological factors emerged as different to each region are average and maximum temperature, minimum dew point temperature and average and maximum wind speed. In the result of correspondence analysis representing relationships between fire causes and study regions, Kangrung is caused by arsonist, Chulwon, Hwachen and Yanggu caused by military factor, Sokcho and Chunchen caused by the debris burning, and Samchuk caused by general man-caused fires, respectively. Finally, the forest fire occurrence pattern of this study regions were divided into five areas such as, group I including Samchuk, Kangryung, Chunchen, Wonju, Hongchen and Hhoingsung, group II including Donghae, Taebaek, Yangyang and Pyongchang, group III including Jungsun, Chulwon and Whachen, group Ⅵ including Gosung, Injae and Yanggu, and group V including Shokcho and Youngwol.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.2
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• pp.81-88
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• 2008

The study was conducted to investigate the effects of DM (dry matter) content and split application of liquid swine manure (LSM) on productivity of rye and subsequent soil quality on the pasture of Livestock Policy Division, Jeju Special Self-Governing Province. The experiment was done between November, 2005 and June 2006, using split plot design. Treatments were 2 main plots (7.0 and 1.6% DM LSM) and 2 subplots (basal fertilizer 100% and basal fertilizer 50%+top dressing 50%). Application of 7.0% DM LSM resulted in significant increase in DM yield and plant length of rye compared with 1.6% DM LSM (p<0.05). Crude protein content of rye was significantly higher in split application(basal fertilizer 50%+ top dressing 50%) than in basal fertilizer 100% (p<0.05). No significant difference in macro and micro mineral contents of rye or in subsequent soil quality was found by application of LSM. Mean P content (0.16%) of rye appeared to be lower than proper P level $(0.2{\sim}0.4%)$ of grass crop. The pH (5.5), OM (13.3%), available $P_2O_5$ (47.6 mg/kg) and Ca (2.75cmole/kg) content of the pasture soil studied were lower, compared with those of cultivated soil. Results show that the application of a 7.5% DM liquid swine manure increases the productivity of rye compared with a 1.6% DM liquid swine manure, meanwhile the property of pasture soil was not influenced by application of LSM.

• Food Science and Preservation
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• v.21 no.1
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• pp.129-139
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• 2014

This study was conducted in order to investigate the optimal fermentation periods of the Smilax china L. leaves as a fermented tea via Aspergillus oryzae for 0 (non-fermented), and 10, 20, and 30 days (NF, F10, F20, F30). It was also observed for its quality characteristics. In the color and spectrum (400~700nm) of 1% tea water extract, NF was light yellow, whereas fermented tea (F10~F30) was light red color, and the F10 among F10~F30 has the clearest color and spectrum. Furthermore, acceptabilities of aroma and brightness were insignificantly different between NF and F10~30, while the mouth feel and overall acceptabilities were insignificantly distinct among all of the fermented teas. Therefore, these results suggest that the appropriate fermentation period for tea fermentation is 10 days. On the other hand, the total polyphenol and flavonoid content in the NF was the highest among all of the fermented teas. In the antioxidant parameters, EDA (electron donating ability), FRAP (ferric reducing antioxidant power), and LPOIA (lipid peroxidation inhibitory activity) in the NF were the highest among all fermented teas. Meanwhile, the XOI (xanthine oxidase inhibitory activity) was low, as well as insignificantly different from NF and F10~F30, whereas the AOI (aldehyde oxidase inhibitory activity) was markedly higher (38.09~41.70%) by the hot water tea extract (with or without fermentation), particularly the AOI that has increased via fermentation. In conclusion, the overall antioxidant activity tended to be reduced by fermentation; however, the EDA, FRAP and LPOIA in the fermented tea for 10 days was higher than the activities during 20~30 days of fermentation. There was a similar result in the color and acceptability of fermented tea for 10 days, which was remarkably better than those of 20-30 days. Therefore, fermented tea from the leaves of Smilax china L. could be expected to be used as a functional tea without the loss of inhibitory activity of both the XO and AO via fermentation.

• Journal of Bio-Environment Control
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• v.29 no.2
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• pp.171-180
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• 2020

The effect of three different light qualities on growth, photosynthesis, quality and safe parameters of hydroponic cultivated spinach (Spinacia oleracea L.) were investigated indoor. Three different light qualities were created of red (660 nm), blue (450 nm) and green (550 nm) LEDs corresponding at ratio R660/B450 = 4/1 (RBL); R660/B450/G550= 5/2/3 (WWL); R660/B450/G550 = 1/1/1 (WL), which were tested at the same intensity (PPFD =190 μmol m^-2 s^-1). The results showed that the plant height and leaf number were the lowest in WL treatment. The SPAD, Net photosynthesis rate Pn, Fv/Fm, Leaf area index LAI values and all parameters of root characteristics were the highest in RBL treatment and were significantly different from two others. Fresh weight of stem, leaf and root, dry weight of root in the three light qualities were significantly different. In contrast, the highest K⁺ content in WL was different from WWL and RBL treatments, while Ca²⁺ and Fe²⁺ content were the highest in the RBL treatment. Vitamin C content was significantly different between the three treatments. nitrate and oxalic acid contents were the highest in WL treatment, whereas soluble-solids contents and vitamin C contents were the highest in RBL treatment. Oxalic acid, nitrate contents were observed tending reduced under WWL although oxalic acid content in RBL treatment was not different from WL and WWL treatments. In all three different light treatments were not detected Salmonella, E.coli. Our results suggest that RBL may be appropriate light for growth of spinach, but supplementary green light to a combination of red and blue LEDs at the reasonable rate can change the quality of spinach in a positive direction. Hydroponic cultivated spinach was safe for users.

• Food Science and Preservation
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• v.18 no.4
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• pp.535-545
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• 2011

The nutrient composition, including the proximate composition and the mineral, vitamin, amino acid, and free-amino-acid levels, of baechu kimchi (Chinese cabbage kimchi) to which 14 kinds of seafood (flatfish, yellow corvina, sea beam, pollack gizzard shad, ray, gray mullet, skate, hairtail, anchovy, sea squit, pen shell, scallop, small octopus)were added was analyzed. The seafoods were added to salted cabbage at concentration of 10% (w/w) and the prepared seafood baechu Kimchi (BK) was stored at $5^{\circ}C$ for seven days. The levels of moisture (82.09-88.56%), crude lipid (0.31-0.64%), and crude ash (2.70-3.50%) did not differ much among the samples, but the level of crude protein of the BK-with-seafood samples (2.42-5.15%) was greater than that of the control BK (2%), without seafood. The Fe and Ca contents of BK with flatfish showed the highest values (4.1 and 74 mg/100 g, respectively). The vitamin A contents of BK samples with 14 different kinds of seafood were higher than that of the control BK. Moreover, the BK with sea squit had higher vitamin $B_2$ (0.90 mg/100 g) and vitamin C (8.48 mg/100 g) contents among all the BK-with-different-kinds-of-seafood samples. Total amino acids were detected in all BK-with-seafood samples, most of which had high levels of glutamic acid, aspartic acid, proline and alanine. Glutamic acid was the most abundant of all the amino acids. The major free amino acids were hydroxyproline, glutamic acid, alanine, proline, leucine, and valine, of which hydroxyproline was the most abundant. In conclusion, BK with seafood is thought to be a very good source of protein, which is very important from dietary life of humans.

• Journal of Applied Biological Chemistry
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• v.57 no.2
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• pp.145-152
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• 2014

To evaluate the improving effects of antioxidant activity, we observed antioxidant capacities such as electron donating ability (EDA), Ferric reducing antioxidant power (FRAP), inhibitory activity of xanthine oxidase (XO) and aldehyde oxidase (AO), and sensory characteristics on mixture of Smilax china L. root water extract added with water extract of fermented S. china L. leaf by Aspergillus oryzae (FSCL). Those contents of mixture with higher ratio of FSCL were proportionally high. And OD475 of mixture with higher ratio of FSCL was almost proportionally high ($R^2=0.9850$). Antioxidant capacities of EDA and FRAP of the mixture was higher than that of non-mixture. In addition, XO inhibitory activity ($IC_{50}$) of A (1.19) was 59.80% higher than that of F (2.96), and the activity of mixture by the higher ratio of FSCL was proportionally low ($R^2=0.9490$). Taste acceptability of A was slightly higher than that of F, whereas that of C was highest. And color acceptability of 40-80% mixture was higher than those of A, F, and B. Overall acceptability of C and D was highest than those of others. Moreover, hot water extract of S. china L. leaf fermented with A. oryzae was maroon color, which looks like Puerh tea style, and mixture of S. china L. root extract added with hot water extract of S. china L. leaf was high acceptability of beverage. These results suggest that mixture of extract of S. china L. root and hot water extract of S. china L. leaf fermented with A. oryzae could improve antioxidant activities.

• The Korean Journal of Mycology
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• v.10 no.1
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• pp.33-39
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• 1982

Carpophores of ten Korean strains of Lentinus edodes (Berk.) Singer, an antitumor polysaccharide producing fungus, were extracted with 0.1N NaOH solution. The extracts were dialized for seven days in distilled water and lyophilized to produce crude polysaccharide powders. Thus obtained crude polysaccharide samples were assayed for sugar contents by colorimetric method with anthrone reagent. Among ten strains examined Lentinus edododes-DMC7 was found to be the richest strain in polysaccharide content of carpophores. By shake culture experiment for biomass production, L. edodes-DMC7 was found to be the second most productive strain among seven strains examined. Cultural characteristics of L. edodes-DMC7 were investigated by shake culture method. The best result was obtained when L. edodes-DMC7 was cultured in the medium containing glucose 8g, starch 80g, yeast extract 12g, $KH_2PO_4\;0.87g,\;MgSO_4{\cdot}7H_2O\;O.5g,\;CaCl_2\;0.3g,\;FeSO_4{\cdot}7H_2O\;10mg\;ZnSO_4{\cdot}7H_2O\;4mg,\;CuSO_4{\cdot}5H_2O\;lmg,\;MnCl_2{\cdot}4H_2O\;7mg\;per\;11\;at\;28^{\circ}C$, 180 rpm, for 12 days. Thus thirty-three grams of dry mycelia was obtained per one liter of medium.