• Journal of Korean Society of Forest Science
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• v.81 no.4
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• pp.325-336
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• 1992

The successional status and potential natural vegetation were examined in a mixed broadleaved-Abies forest located at Mt, Odae National Park. The examination was based on the subsequent process of generation replacement by understory saplings for the dominant canopy trees within 88 $5m{\times}50m$ belt transects. The transition matrix model, which was modified from mathematical theory of Markov chain, was employed to analyze the successional status of the study forest. The model suggests that the study forest is still seral, and it is considered to be more than 700 years away from the steady state or climax in terms of species composition. The simulations predict a remarkable decrease in the proportion of species composition of the present dominant Quercus mongolica and Tilia amurensi.s from current 28% and 13% to less than 3% and 5%, respectively, at the steady state. On the contrary, the proportions of Abies holophylla, Acer pseudo-sieboldianum, Carpinus cordata, and Pinus koraiensis will increase at the steady state. The ratio of mixture between deciduous and coniferous trees will be gradually changed from current 6.5 : 3.5 to 5.0 : 5.0 at equilibrium. Discussion for the problems of Quercus mongolica in successional status noted that the species behaved as a mid-successional dominant, not a climax species in the study forest. The hypothesis and sensitivity of the transition matrix model were also discussed to evaluate the applicability to the real situation. The overall results indicated that the present dynamics of the forest must reflect the seral state due to previous disturbance mainly by hyman related interference.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.30 no.5
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• pp.201-206
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• 2018

This study investigated the changes in pore water quality of polluted sediment by mixing ratio of granulated coal ash. The mesocosm experiments were carried out with 0%, 10%, 30% and 50%, respectively, of the material mixture ratio relative to the sediments. According to the results of the experiments, pH increased depending on the mixing ratio. Phosphate and ammonia concentrations were significantly decreased in the mixing ratio of 30% and 50% compared to the control (p < 0.05). The concentration of hydrogen sulfide was reduced by 72% at the mixing ratio of 10%, and it was not detected at the mixing ratio of 30% and 50%. This study was confirmed that granulated coal ash can change the pore water quality of polluted sediments in proportion to the amount of material. However, the effect of the mixing ratio between 30% and 50% was not significantly different, thus it is concluded that mixing of 30% of the volume of the sediment is economically feasible.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.3
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• pp.51-62
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• 2005

The effects of the processing mixture of food wastes and various organic wastes when vermicomposted on earthworm(Eisenia foefida) growth, the cast production amounts and the chemical properties of casts were evaluated. The substrates used in this experiments were cow manure, pig manure sludge, fermented pig manure with sawdust, nightsoil sludge, and sewage sludge and were respectively mixed with food wastes at a ratios of 50:50(v/v). The control consisted of food wastes alone without other wastes. All of earthworm died in the food wastes 100%, therefore the process of food wastes alone by vermicomposting was impossible in this experiment. Worm cast produced sufficiently contained quantities of available phosphorus, exchangeable potassium, exchangeable magnesium, and cation exchange capacity. The increase of earthworm's biomass occured on the mixtures of food wastes and cow manure, fermented pig manure with sawdust. Dry weight of worm cast was the highest on the mixtures of food wastes and fermented pig manure with sawdust and the proportion of cast weight after vermicomposting was significantly the highest on the mixtures of food wastes and cow manure($p{\leq}0.05$). Also, the mixtures of food wastes and cow manure, and fermented pig manure with sawdust showed a positive values of conversion rate and conversion efficiency rate of organic matter to earthworm tissue than that of other treatments. These results suggested that cow manure and fermented pig manure with sawdust are adequate to process with food wastes by vermicomposting.

• Journal of Nutrition and Health
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• v.23 no.2
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• pp.135-147
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• 1990

This study was devised to observe the cytotoxic activities of garlic extracts against various cancer cells, that is, murine leukemic lymphocyte(L1210 and P388) and human rectal(HRT-18) and colon cancer cells(HCT-48 and HT-29) in vitro, and murine ascitic tumor cell(S-180) in vivo. Each cell-line except S-180 was cultured in medium containing serial concentration of the garlic extract in vitro. Inhibitory effect n the growth rate of the cancer cells was stronger in extracts of petroleum ether than that of ethanol. A lipid soluble compound in the extracts of garlic was cytocidal to murine leukemic cells, human rectal and colon cancer cells in vitro. The growth rates of the cancer cells in medium containing garlic extracts were inhibited gradually to a significant degree in proportion to the increase of the extract concentration. The cytotoxic activity of garlic active fraction from TLC was about 2.3 times more potent than that of crude garlic extract, one unit of cytotoxic activity against L1210 cells being equivalent to 4.2$\mu\textrm{g}$ and 1.8$\mu\textrm{g}$ from the crude garlic and active fraction, respectively. The Rf value of the active fraction on silica-gel TLC was 0.18 in condition that petroleum ether/ethyl ether/acetic acid mixture(90:10:1, v/v/v) was used as a developing solvent. The survival times of mice inoculated with S-180 cells were extended about 1.5 to 2 times in the groups treated with garlic extract(through i.p. and oral administration) compared with their control group(no garlic extract treatment). Observations were carried out on S-180. Ethanol extracts of garlic injured markedly tumor cells within 3 hours after injection.

• The Korean Journal of Mycology
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• v.46 no.3
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• pp.325-331
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• 2018

We aimed to increase the utility of Broussonetia kazinoki (paper mulberry) by using its woody parts as a substrate for Lentinula edodes cultivation. Using different mixing ratios of paper mulberry and oak tree sawdust, five types of column-type media were prepared (1.2 kg each). Two L. edodes strains (NIFoS 2462 and NIFoS 2778) were used in this study. In the first flush, numerous small mushrooms were harvested because the fruited mushrooms were densely packed on the small media. The highest productivity was obtained with a 3:1 mixture of paper mulberry and oak tree sawdust (Q. acutissima:Q. mongolica, 1:1). In particular, for NIFoS 2462, the proportion of paper mulberry in the medium positively correlated with productivity. The size of NIFoS 2778 was uniform in all media tested. By contrast, the mushroom weight of NIFoS 2462 decreased, but the other characteristics were not significantly affected. Collectively, these findings suggest that B. kazinoki sawdust could be used to grow shiitake mushrooms and that some oak sawdust substitution is also possible. Our results could increase the utility of discarded by-products, such as sawdust.

• Korean Journal of Environmental Agriculture
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• v.19 no.2
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• pp.128-133
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• 2000

This study was conducted to investigate the adsorptive characteristics with cadmium in different levels of organic matter and lime in soil. And in order to identify the effect of soil ameliorators on cadmium uptake in rice plants, compost and lime were treated. Plants were grown at two soil textures(sandy loam and clay loam) with irrigation water containing $0.01\;mg\;L^{-1}$ of cadmium and treatments of two irrigation systems(intermittent irrigation and continuous submersion). The adsorption capacity of cadmium by soil was increased in proportion to initial concentration of solution, and it was higher at clay soil compared to loamy soil. The adsorption rate of cadmium by soil was increased with increasing the concentration of organic matter and lime in soil, highly increased at the both organic matter and lime treatment. Soil pH was negatively correlated with the cadmium contents of the both shoot and brown rice while Eh was positively correlated with those. In the harvest season, cadmium contents in the both leaves and brown rice were lower in the clay sail plots than sandy soil plots, and the continuous submersion plots were lower than intermittent irrigation plots. Cadmium uptake was highly reduced at the compost and lime mixture plot compared to other treatments among the continuous submersion plots. The cadmium content of shoot was positively correlated with that of brown rice in the harvest season.

• Korean Journal of Organic Agriculture
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• v.13 no.1
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• pp.85-99
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• 2005

This trial was carried out to determine effects of organic feeds in comparison to conventional diet on feed intake, digestibility, and nitrogen retention in Korean native goats. Twelve Korean native goats were allotted to treatments in four groups of three goats and then they were housed in separate metabolism cages for 21 days. Treatments included conventional diet (A) as a control group and three organic feed groups (B: organic rice straw, C: organic nee leaves, D: organic mixture of rice straw and tree leaves). The A treatment, conventional diet, consisted of common rice straw and commercial concentrates at a proportion of 60 and 40%, respectively. All ingredients of organic feeds treatments were organically produced-agricultural products without any application of chemical fertilizer and pesticide. Four experimental diets were formulated to have the same ratio of forage to concentrate and similar contents for protein and carbohydrate across treatments and they were offered to goats ad libitum. Feed intake, apparent nutrient digestibility and nitrogen retention were investigated. For chemical compositions of experimental diets, all nutrients except crude ash and ether extract were not significantly different across treatments as we expected. Crude ash content was highest in the A treatment (P<0.05), however, it was not significantly different among organic feeds treatments. Ether extract content was higher (P<0.05) in C and D treatments than in A and B. Even if dry matter intakes for organic feeds treatments were not significantly different among them, they were significantly higher (P<0.05) compared with conventional diet. Fecal excreta were not significantly different across treatments, resulting in significantly higher digestible dry matter (g/day) in treatments of organic feeds (P<0.01). Average daily gain (ADG) and feed efficiency (FE) were more increased (P<0.01) in treatments of organic feeds compared with conventional diet. Digestibilities for most of nutrients except NFC had the same trend as ADG and FE, however, NFC digestibilities for C and D treatments were significantly lower (P<0.01) than those of A and B. Nitrogen intakes for organic feeds treatments were significantly higher (P<0.001) than conventional diet, with no difference among organic feeds treatments. Fecal nitrogen loss was higher (P<0.05) for C and D treatments than for A and B. Retained nitrogen contents were significantly higher (P<0.05) for organic feeds treatments than for conventional diet, but nitrogen retention rate did not show any difference across treatments. The results showed that organic feed supplementation more improved feed intake, digestibility and nitrogen retention in comparison with conventional diet, and thus they could be concluded that organic feeds might contribute to animal performance and a safer production of animal product.

• 한국유가공학회:학술대회논문집
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• 2005.06a
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• pp.37-61
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• 2005

Microcapsules consisting of natural, biodegradable polymers for controlled and/or sustained core release applications are needed. Physicochemical properties of whey proteins suggest that they may be suitable wall materials in developing such microcapsules. The objectives of the research were to develop water-insoluble, whey protein-based microcapsules containing a model water-soluble drug using a chemical cross-linking agent, glutaraldehyde, and to investigate core release from these capsules at simulated physiological conditions. A model water soluble drug, theophylline, was suspended in whey protein isolate (WPI) solution. The suspension was dispersed in a mixture of dichloromethane and hexane containing 1% biomedical polyurethane. Protein matrices were cross-linked with 7.5-30 ml of glutaraldehyde-saturated toluene (GAST) for 1-3 hr. Microcapsules were harvested, washed, dried and analyzed for core retention, microstructure, and core release in enzyme-free simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) at 37$^{\circ}C$, A method consisting of double emulsification and heat gelation was also developed to prepare water-insoluble, whey protein-based microcapsules containing anhydrous milkfat (AMF) as a model apolar core. AMF was emulsified into WPI solution (15-30%, pH 4.5-7.2) at a proportion of 25-50% (w/w, on dry basis). The oil-in-water emulsion was then added and dispersed into corn oil (50 $^{\circ}C$)to form an O/W/O double emulsion and then heated at 85$^{\circ}C$ for 20 min for gelation of whey protein wall matrix. Effects of emulsion composition and pH on core retention, microstructure, and water-solubility of microcapsules were determined. Overall results suggest that whey proteins can be used in developing microcapsules for controlled and sustained core release applications.

• Korean Journal of Food Science and Technology
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• v.26 no.3
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• pp.266-271
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• 1994

The curd yogurt (total solid content: 14%) was prepared from milk added with skim milk powder and potato puree. Potato puree comprised 9.5. 13,8 and 17.9% (dry basis) of the milk-potato mixture, and the effect of potato on the quality of yogurt was investigated. Addition of potato remarkably stimulated acid production and propagation of lactic acid bacteria, and viable cells reached above $3.9{\times}10^{10}$ CFU/ml after 12 hours. As potato content increased, the ratio of lactic acid content to total acidity decreased, while citric acid increased. The major organic acids of yogurt were lactic acid, citric acid, and acetic acid. Viscosity of yogurt was increased in proportion to the increment of the potato content. After 24 hours of incubation, the sensory score of yogurt containing 13.8% (dry basis) potato showed better sensory acceptability. When curd yogurt added with potato was kept at $5^{\circ}C$ for 15 day, its keeping quality was relatively good. Viable cells of lactic acid bacteria and ${\beta}-galactosidase$ activity decreased rapidly at pH 1.5, and 2.5, but the group added with potato was more stable than control.

• Food Science and Preservation
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• v.24 no.5
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• pp.585-592
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• 2017

The purpose of this study was to prepare blueberry syrup (cheung) using fructooligosaccharide instead of the traditionally used sucrose. The sugar content, pH, and colorimetric values were measured to evaluate the quality of the prepared syrup, and the antioxidant activity and phenolic compound content were determined to assess the physiological activity of the syrup. The $L^{\ast}$ value (lightness), pH, and color were high in syrups containing a high proportion of fructooligosaccharide. The $a^{\ast}$ value (redness) was high in syrups subjected to heat treatment, and the $b^{\ast}$ value (yellowness) tended to be the opposite of the $L^{\ast}$ value. Moreover, syrups containing heat-treated fructooligosaccharide showed higher polyphenol, flavonoid, and anthocyanin contents than the unheated syrups did. The antioxidant activity of the blueberry cheung depended on the content of phenolic compounds. The highest value was obtained in the cheung prepared using a heat-treated 1:1 mixture of blended raw blueberry and fructooligosaccharide (S2). These findings suggest that our familiarity with the taste of the sweetener used influences our taste preference. It is therefore necessary to study other newly developed sweeteners apart from fructooligosaccharide to find a suitable alternative to sucrose.