• Korean Journal of Soil Science and Fertilizer
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• v.49 no.6
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• pp.705-711
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• 2016

Crimson clover, a legume crop, is a landscape crop and green manure crop that can be sowing in spring and autumn. Its red flower blooms in May, and serves various roles such as landscape composition, weeds suppressing, prevention of soil loss and nutrient on sloping land and supplying nitrogen and organic matter in soil. Thus, in order to utilize this crop in agriculture land, we evaluated the growth characteristics of crimson clover cultivated in four different soil textures; sand, sandy loam, loam, and clay loam. The nitrogen content of crimson clover was $15.8g\;kg^{-1}$ and C/N ratio was 20.3. Its plant height was 42.5 cm in sandy loam and 49.5 cm in loamy, respectively, approximately 20 cm longer than the sand and clay loam. The crimson clover in sandy loam and loam bloomed about seven days earlier than those in sand and clay loam. Regarding number of flower per hill and flower length, there were no difference among the soil textures. Dry weight of crimson clover for sandy loam and loam was $2.5Mg\;ha^{-1}$ and $2.3Mg\;ha^{-1}$, respectively, $0.8{\sim}1.1Mg\;ha^{-1}$ higher than that of sand and sandy loam. Plant height and dry weight of crimson clover increased with delaying harvest time. Nitrogen contribution in loam and clay loam was $51.3kg\;ha^{-1}$ and $53.5kg\;ha^{-1}$, respectively. Therefore, in terms of flowering properties and dry weight, the proper soil texture for the growth and development of crimson clover was sandy loam and loam.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.6
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• pp.644-650
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• 2016

In soil-to-plant transfer of heavy metals, the amount absorbed and accumulated varies depending on the environment conditions. The absorption rate of cadmium (Cd) in plants differs considerably depending on the bioavailability of Cd in the soil, while usage by various organic matters is also reported to affect absorption patterns. Therefore, this study aimed to identify the difference in the transfer of essential metal ions and Cd to various plant parts when rice straw compost was used to cultivate soybean (Glycine max L. cv. Daepung). In the two-leaf stage of soybean cultivated in a greenhouse, Cd was mixed in the soil, after which the Cd and essential metal ions contents, and physiological changes of soybean seedlings were studied on the 15th and 25th day. The Cd toxicity in the plant was reduced with the use of rice straw compost. Further, the Cd content varied with the plant part, and was higher in young leaves (3rd and 4th leaf) than in the stem. When analyzed by leaf age, the Cd transfer was highest in young leaves (3rd and 4th leaf), followed by mature leaves (1st and 2nd leaf). While there was no significant difference between plant tissues in the absorption rate of copper (Cu) and zinc (Zn) when rice straw compost was used against Cd toxicity, the absorption rate of manganese (Mn) and iron (Fe) showed a significant decline in both the control and rice straw compost treatment conditions, as well as a significant difference between leaf ages. Therefore, these results confirm that the use of rice straw compost against Cd toxicity is effective, and implies that the rate of Cd transfer in the soybean plant varies significantly with leaf age.

• Membrane Journal
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• v.15 no.2
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• pp.165-174
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• 2005

Sulfonated poly(styrene-ethylene-butadiene-styrene) (SSEBS)-clay hybrid membranes were prepared by solution method. In the preparation of hybrid membrane, the amount of clay content was fixed to 5 phr and montmorillonite (MMT) was fully exfoliated by the SEBS and it was confirmed by X-ray diffraction method. D-spacing of the characteristic peak from MMT plate in WAXD was fully diminished. Gas permeability, mechanical properties and thermal properties of the SSEBS-clay hybrid membranes were investigated. Gas permeability through the SSEBS-clay hybrid membranes decreased due to increased tortuosity made by exfoliation of clay in SEBS.

• Korean Journal of Medicinal Crop Science
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• v.15 no.2
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• pp.138-141
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• 2007

Good quality seedlings produced in the seedbed of Yangjik, traditional seedling cultivation, is one of the most important factors in determining the yield and quality of $4{\sim}6-year-old$ ginseng. This study was carried out to substitute Yacto, traditional organic fertilizer, for economical compost in the cultivation of seedling by fertilizing relatively little amount of compost into seedbed soil. Bulk density and solid phase were decreased in physical properties of seedbed soil, while air phase and porosity were increased by more addition of compost. When the amount of applied compost in seedbed soil was above $8{\ell}$ per Kan, the contents of nutrient were exceeded the range of optimal standard for ginseng cultivation. Chlorophyll content and stem length were increased by more addition of compost, while the length and the width of leaves showed the highest value at the application level of $8{\ell}$ per Kan. Heat injury was also increased distinctly above the application level of $8{\ell}$ per Kan. The number of first grade seedlings and usable seedlings, and fresh root weight per plant showed the peak at application level of $8{\ell}$ per Kan, respectively. Fertilizing the compost of $8{\ell}$ per Kan into seedbed soil was the optimal amount for producing the good quality seedlings.

• Journal of Environmental Health Sciences
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• v.24 no.1
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• pp.112-119
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• 1998

The objective of this study was to investigate the effect of bulking agents including cow manure, saw dust and rice straw in the ripening of leather sludge for vermistabilization. The changes of the waste properties for ripening time for 50 days were observed according to the various mixture ratios of leather sludge and bulking agents. The pH values of the mixture wastes were decreased from 7.5-8.0 to 6.4-7.3 with the ripening time for 50 days, and it was indifferent of the mixture ratio and type of the bulking agent. The initial value of oxidation-reduction potential(Eh) of the mixture waste was a negative(-)value indicating an unfavorable condition for earthworm life, but the values of Eh were increased with the ripening time. The increase rate of Eh value was proportional to the mixture ratio of bulking agents, but the increase rate for saw dust was higher than that of the cow manure and the rice straw. The value of alkalinity was also changed into the favorable range for earthworm after 50 days except for 10% of the mixture ratio of the bulking agents. When the mixture ratios of the bulking agents were increased from 10% to 40%, the growth characteristics of earthworms were increased from 31.7% to 95% for the survival rate, 103% to 225% for the liveweight increase rate and 32% to 91% for hatching rate of the cocoons. It can be concluded that the proper content of the bulking agents in the leather sludge to ensure effective vermistabilization was over 30%, when the mixture was ripened during 50 days. The contents of heavy metals in the ripened sludge were lower than the other regulatory standards for compost.

• Journal of Environmental Science International
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• v.14 no.2
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• pp.105-119
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• 2005

The surface sediments inside Songsanpo and Seogwipo Harbors, major harbors of Jeju Island, were collected three times (June, September and December, 2001) and analyzed for 16 polycyclic aromatic hydrocarbons (PAHs) recommended by US-EPA as priority pollutants to assess their distribution levels and their biological effects on the marine organisms, and to suggest their possible origins. The concentrations of total PAHs inside Songsanpo and Seogwipo Harbors ranged from 41 to 288 ng/g on a dry weight basis with a mean value of 121 ng/g and from 14 to 268 ng/g with a mean value of 119 ng/g, respectively, and the levels were low as compared with those in other areas of the world. The sedimentary PAHs may be correlated with organic carbon and mud content to some extent. Based on comparisons of individual and total concentrations with effects-based sediment quality guidelines, the potential for the biological effects on the marine organisms were expected to be very low. From the examinations of the four PAH origin indices, such as LMW /HMW (low molecular weight 2-3 ring PAHs over high molecular weight 4-6 ring PAHs), phenanthrene/anthracene ratio, fluoranthene/pyrene ratio, chrysene/benzo[a]anthracene ratio, it can be concluded that the sediment PAH contaminations were ascribed to both of pyrolytic and petrogenic origins.

• The Korean Journal of Ecology
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• v.14 no.2
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• pp.159-169
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• 1991

Floristic cmposition and soil properties were analyzed in chines cork oak(quercus variabilis)cmmunities in the limestone area, tanyang, ch'ungbuk province in korea. The tree layer was composed of quercus dentata, platycarya strobilacea, fraxinus rhynchophylla and others as wel as quercus variabilis. the shrub layer was dominated by ulmus davidiana for. suberosa,shrubby q. variabilis. euonymus alatus and rhus chinensis. among these, u. davidiana for. suberosa was known to have a restricted distribution to calcareous area, and 9 species in the shrub layer including e. alatus, indigofera kirilowii and rhamnus davurica belonged to the calcicole. The herb layer was dominated by carex lanceolata and spodiopogen cotulifer. ten specirs including g. lanceolata, clematis mandshurica, isachne globosa, lithospermum arvense and scabiosa mansenensis belonged to the calcicode. soil texture was classified to clay loam in both top and subsoil. Water cotent and organic matter were consistentl higher in top soil than in subsoil. soil ph rangd 7.8~8.4. Total n concentration in top soil ranged from 0.2 to 0.4mg/g, which was higher than that in subsoil. Available p and exchangeable k concentretion were also significantly higher in op soil than in subsoil. However, exchangeable ca concentration was similar betweenthe top and the subsoil. Unlike the other nutrients, exchangeable mg concentration in top soil was lower than that in subsoil. orangic matter, n, p and k content in this chinese cork oak stand showed as much as the other noncalcareous sites. Soil properties in this study area seemed to have been influenced by casts forming activities of earthworms.

• Culinary science and hospitality research
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• v.23 no.5
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• pp.25-33
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• 2017

This study was to investigate the effects of enzyme on quality characteristics and antioxidant activities of wild peach (Prunus persica L.) juice. pH levels and S.S (soluble solid) values in all samples ranged from 3.86 to 4.13 and from 48.0 to $55.0^{\circ}Brix$, respectively. The TA (total acidity) values of control (not treatment enzyme) were higher than those of the others. The highest 'L', 'a' and 'b' values were observed on PWP (preserved wild peach (Prunus persica L.) juice of cellulase/pectinase (1:1, w/w) sample. Glucose (26.65 g/100 g) and fructose (17.42 g/100 g) in PWP product were determined, however sucrose and maltose were not detected. The predominating organic acid components analyzed in PWP sample were tartaric (32.36 g/100 g) and lactc acids (209.34 g/100 g), whereas citric acid, acetic acid and malic acid were not detected. Higher scores for taste, flavor, color and overall acceptance were found for PWP products compared to other samples. The total phenolic content (13.31 mg GAE/mg dry weight) analyzed using Folin-Ciocalteu's reagent, of PWP sample was higher than those of the others and the total flavonoid concentrations were also 10.95 mg CE/mg dry weight. The DPPH radical scavenging and ABTS radical scavenging activities in all samples ranged from 55.16 to 74.29% and from 39.59 to 82.79%, respectively. The antioxidant activities were affected by addition of enzyme. These results indicate that the use of the mixture of cellulase and pectinase could increase the quality, and antioxidant potentials of sugar preserved wild peach (Prunus persica L.) juice by enzymatic treatment.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.945-948
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• 2008

Fire resistance is a measure of the ability of building element to resist a fire. For concrete columns, the fire resistance depends on many factors, including strength, density, and moisture content of concrete, fire intensity, column size and shape, reinforcement detail, loading condition, and aggregate type etc. However, it is well-known that the high strength concrete (HSC) is more susceptible to spalling than normal strength concrete (NSC) and the behaviour of HSC column exposed to fire is significantly affected by the spalling. Recently, as one of the measures to reduce the spalling of HSC, incorporating polypropylene(PP) fiber has been investigated and successfully used in construction fields. However, the establishment of assessment method on the fire resistance of HSC column is very important as well as the improvement of fire performance of HSC. In this study, the variations on the fire resistance of HSC column with assessment methods was studied for the columns controlled the concrete spalling by PP fiber.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1330-1336
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• 2008

Here we studied the changes on quality characteristics of Dongchimi by supercritical carbon dioxide to manufacture Dongchimi of high quality. There were no distinctive changes of acidity, pH, color difference, free sugar and organic acid of the Dongchimi treated with supercritical $CO_2$, compared to the control. The content of vitamin C in Dongchimi, which was treated with supercritical $CO_2$ (at 25 MPa, $35^{\circ}C$) was 0.826 mg/mL, and was similar to that of 0.1 MPa. Unpleasant volatile compounds such as dimethyl disulfide, metyl trisulfide and methyl propyl disulfide in Dongchimi were decreased by supercritical $CO_2$; also, treatment of supercritical $CO_2$ was useful to improve flavor of Dongchimi. Polygalacturonase activity was decreased 40.3% after supercritical carbon dioxide treatment at 25 MPa and $55^{\circ}C$.