• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.6
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• pp.26-37
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• 2008

The purpose of the study was to evaluate the effect of pervious pavements on reducing the surface runoff caused by rainfall. The surface runoff from twelve steel experimental beds with different pavement had been recorded every minute from May to September 2008, by the measuring system of tipping buckets(0.1mm/count) and data aquisition systems(National Instrument's Labview and DAQ boards & Autonics PR12-4). The dimension of the experimental bed was $1.5m(W){\times}2.0m(L){\times}0.6m(D)$ and eleven different kinds of vegetational(grass, grass+cubic stone, grass+hole brick), modular(brick, cubic stone, small cubic stone, wood block, interlocking block, clay brick, granular clay brick) and granular(naked soil, gravel) paving materials and concrete were applied for the comparison. Six rain events with depth over 30mm were selected and compared. The maximum depth of the rainfall selected was 137.5mm for 28 hours, and the minimum 30mm for 5 hours. The maximum rainfall per hour was 23mm/hr and the minimum 11.4mm/hr. The major findings were as follows; 1. All pervious pavement applied reduced over 75% of the surface runoff compared with concrete pavement. The grassy and porous pavements were relatively efficient in reducing surface runoff. 2. The grass was the more efficient as intercepting average 69.5mm of initial surface runoff, and maximum 77.8mm at the condition of 13.5mm/hr rainfall. The next was gravel intercepting maximum 65.5mm at the condition of 13.5mm/hr and the 40.9mm at 19.1mm/hr, average 55.7mm. 3. The modular pavements common in urban area were not good in intercepting the runoff except the 'clay granular brick' compared with others. The 'clay granular brick' showed relatively efficient intercepting average 14.1mm, which was the bigger amount than the 'grass+hole brick'. 4. The 'naked soil' were more effective than the 'concrete', 'brick', and 'interlocking block' in reducing the surface runoff, but less efficient than other materials. The capacity of the 'naked soil' to intercept the initial rainfall was similar to the 'brick'. As summary, the more grassy and porous pavement shows more effective in reducing surface runoffs.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.195-203
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• 2015

Quintozene, pentachloronitrobenzene (PCNB) is a contact fungicide for control of soilborne phytopathogenic fungi during cultivation of diverse crops. It was introduced to agricultural use around 1930's as a substitute for mercurial disinfectants. Although quintozene had been first registered in Korea on 1969. However, now it was banned to use due to its high residue levels in selected harvest products. Also, high possibility is expected that the residue may be contained in imported agricultural commodities as it is still used widely over the world. Therefore, this study was conducted to establish a determination method for quintozene residue in crops using GC/ECD/MS. Quintozene residue was extracted with acetonitrile from representative samples of five raw products which comprised hulled rice, soybean, Kimchi cabbage, green pepper, and apple. The extract was diluted with saline water, and n-hexane partition was followed to recover quintozene from the aqueous phase. Florisil column chromatography was additionally employed for final clean up of the extract. The quintozene was quantitated by GLC with ECD, using a DB-1 capillary column. The crops were fortified with quintozene at 3 levels per crop. Mean recoveries ranged from 79.9% to 102.7% in five representative agricultural commodities. The coefficients of variation were less than 4.3%. Quantitative limit of quintozene was 0.004 mg/kg in representative five crop samples. A GC/MS with selected-ion monitoring was also provided to confirm the suspected residue. Therefore, this analytical method was reproducible and sensitive enough to determine the residue of quintozene in agricultural commodities.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.37 no.4
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• pp.347-350
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• 2011

Biofilms are surface-attached microbial communities with phenotypic and biochemical properties distinct from free-living planktonic cells. Biofilm bacteria show much greater resistance than planktonic counterparts and much higher concentration of biocide is needed to treat biofilms compared to the dosage used for planktonic bacteria. As a result, alternative strategies or more effective agents exhibiting activity against biofilm-producing micro-organisms are of great interest. Therefore, we turned our attention to control of biofilm of S. aureus. The aims of this research are to investigate substances which inhibit the formation of biofilm by S. aureus and to suggest effective materials for controlling skin problems. We coated slide glasses with human placental collagen and the coverslip was incubated with test materials and bacteria. The coverslip was stained with crystal violet and we measured optical density of each sample. The biofilm inhibitory activity was calculated by crystal violet staining degrees. In this study, S. aureus ATCC 6538 was used as test organism. Our results show that both water soluble and insoluble Hinoki cypress polysaccharide strongly inhibited biofilm formation. Whereas, green tea and sunset hibiscus root extract promoted biofilm. Xylitol showed a concentration dependent effect; high concentration (3 % and 5 %) of xylitol reduced biofilm while promoted biofilm formation at a concentration of 1 %. These results support that Hinoki cypress polysaccharide and xylitol have ability to suppress biofilm formation.

• Korean Chemical Engineering Research
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• v.50 no.5
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• pp.890-893
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• 2012

Gas hydrates are solid crystal structures formed by enclathration of gaseous guest species into 3-dimensional lattice structure of hydrogen-bonded water molecules. These compounds can be potentially used as an energy storage/transportation medium because they can hold a large amount of gas in a small volume of the solid phase. In addition, huge amount of natural gas, buried in seabeds or permafrost region in the form of the solid hydrate, is regarded as a future energy source. In this study, synthesized natural gas, whose composition is 90.0 mol% of methane, 7.0 mol% of ethane, and 3.0 mol% of propane, was used to identify formation behaviors of natural gas hydrates for the purpose of applying the gas hydrate to a storage/transportation medium of natural gas. According to the experimental results obtained by means of the solid-state NMR and high-resolution powder XRD methods, it is found that formed natural gas hydrates have crystal structure of the structure-II hydrate, and that methane occupies both small and large cages, while the others only occupy large ones. In addition, both the NMR spectroscopy and the gas chromatograph showed that there exists preferential occupation among the natural gas components during the hydrate formation. Compositional changes after the hydrate formation revealed that the preferential occupation is in order of propane, ethane, and methane (propane is the most preferential guest species when forming natural gas hydrates).

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.4
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• pp.102-115
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• 2011

The purpose of this study is to establish the evaluation model through the systematic process of selecting the indicators and to evaluate the environmental-control function on forest using GIS in Deagu for the sustainable forest planning. The 35 indicators as basic items were selected by literature review and those were squeezed into the 29 indicators through expert brainstorming. Also, the 8 indicators to evaluate environmental-control function were selected by the first survey and the 5 final indicators such as carbon sink, temperature decrease, wind formation, water circulation, air purification were determined by MCB analysis using the second survey. The evaluation model was established through the weight of each indicator by AHP analysis using the third survey. According to the result of evaluating the environmental-control function on forest, the functions around the top area of Mt. Ap, Mt. Biseul, Mt. Palgong had more than 66 scores. On the other hand, the functions around Mt. Waryong and forest of Chilgok in Buk-gu had less than 40 scores. It is necessary to improve the function through the sustainable restoration and management in case of forest that the environmental-control function was lower. Furthermore, these results will be able to be utilized as basic data in order to establish the preservation area and control development area at the urban, environmental, and forest planning.

• Journal of dental hygiene science
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• v.8 no.2
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• pp.89-96
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• 2008

Effects of sodium fluoride exposure on the amelogenesis during fetal formation were investigated using 11 days rat incisor of control group and two experimental groups. According to results of morphological analysis using an electron microscope, enamel organ in the rat incisor consisted of presecretory, secretory, and maturation zone, especially maturation zone had ruffle-ended ameloblasts (rAB) that additionally supply inorganic ions and smooth-ended ameloblasts (sAB) that remove water and organic compounds. Such a histological composition was same in fetal and adult rats. According to experimental results using calcein (green fluorescence) in order to reveal the modulation cycle of ameloblast, modulation cycle of experimental group decreased on an average one time than control group, as increase of density of sodium fluoride indicated that thickness of smooth-ended ameloblast decreased. Also ratio of thickness on sagittal total length of sAB increased than rAB in experimental groups than control group. In total length of teeth, an injected 100 ppm sodium fluoride group was similar control group but as injected 200 ppm group became short. In experimental group, thickness of sAB and rAB became narrow to the tip of cutting edge. According to concentration of sodium fluoride grows, the modulation cycle and total length of teeth were decreased, finally it prevented teeth growth.

• Korean Journal of Ichthyology
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• v.27 no.2
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• pp.86-94
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• 2015

Egg development and early life history of the endangered species, Microphysogobio rapidus was investigated to get a basic information for biological characteristics and recovery strategy. Eggs were obtained from females by injecting Ovaprim (0.5 mL/kg) and artificially fertilized by dry method in the laboratory. The mature eggs were slightly adhesive and separated with light bluish green and $0.63{\pm}0.02mm$ (n=20) in diameter. Number of eggs in the ovaries were $3,827{\pm}1,225$ (2,850 ~ 5,916). The hatching occurred at 72 hours after fertilization under water temperature of $21{\pm}1^{\circ}C$. The newly-hatched larvae were $2.79{\pm}0.04mm$ (n=10) in total length. At 5 days after hatching, they were average $4.10{\pm}0.07mm$ (n=10) in TL and their yolk sacs were completely absorbed. 30 days after hatching, they became to juvenile stage and reached $9.74{\pm}0.24mm$ (n=10) in TL. At 100 days after hatching, the band patterns and external form were similar to those of adults, average $27.00{\pm}1.94mm$ (n=10) in TL.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.5
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• pp.211-216
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• 2008

The artificial lightweight aggregate (ALA) was manufactured in a rotary kiln at $1125^{\circ}C$ using green body formed by pelletizing the batch powder composing of coal bottom ash (CBA) produced from power plant, clay and dredged soil (DS). The TCLP (Toxicity characteristic leaching procedure) results showed that the dissolution concentration of heavy metal ions of ALA fabricated in this study was below the limitation defined by the enforcement regulations of wastes management law in Korea. The ALA containing 60$\sim$70 wt% CBA had a bulk density of 1.45$\sim$1.49 and a water absorption of 17.2$\sim$18.5 %. The impact values for oven-dry state and saturated-surface dry state of ALA were 27.4$\pm$1.3 and 23.4$\pm$2.6 % respectively. The 28-days compressive strength of concrete made with various ALA was $22.7\sim27.8 N/mm^2$. The slump of concrete with ALA containing CBA 60 and 70 wt% were 7.9 and 14.3 cm respectively. The unit weight of concrete made with any ALA fabricated in this study was satisfied with the standard specifications of lightweight concrete for the civil engineering and construction presented by Korea as below $1.84 ton/m^3$.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.9
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• pp.735-742
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• 2009

The bone of spinal animals has a hydroxylapatite ($Ca_{10}(PO_4)_6(OH)_2$, HAp) structure which is well known as an excellent inorganic ion exchanger for various heavy metal ions in solutions. In this study, the reusability of cow-bone, pig-bone and fish-bone as a potential material for the removal of heavy metals in solutions was evaluated from the removal of Cu(II) ion in batch tests. The surface properties of three bones, calcined at different temperatures, were measured with SEM, XRD, FT-IR analyses. From the SEM analysis, a clear development of heterogeneity as well as pores having small diameter was observed as the calcination temperature increased. The results of X-ray diffraction analysis showed well developed crystallinity on the surface of calcined bones obtained at higher temperatures, suggesting a transform of amorphous type to crystalline type. Fourier transform infrared (FT-IR) analysis showed disappearance of water molecule on the surface of HAp and organic functional groups of the HAp with increasing the calcination temperatures. Cu(II) removal in the control test was below 15%. By the way, additional 40% increase of Cu(II) removal was observed in the presence of calcined bones. For three bones, Cu(II) removal was decreased as the calcined temperature increased. Cu(II) removal was increased as the solution pH increased due to a favorable condition for the cation exchange as well as precipitation.

• Journal of Life Science
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• v.18 no.7
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• pp.974-979
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• 2008

The powdery mildew, a fungal plant disease found in varieties of plant cultures, is occurred by attack with Fusarium sp., Sphaerotheca sp., Leveilluna sp., and Eryshipe sp.. In this study we investigated the control of Fusarium graminearum, a barley powdery mildew fungus, by natural plant extracts. Among the 900 plant extracts tested, Zanthoxylum schinifolium, Ligusticum acutilobum, Bidens frondosa L., Dictamnus dasycarpus, Evodia officinalis, Disporum sessile, Scopolia japonica Max., Styrax japonica S. et Z., Dictamnus dasycarpus Turcz., Sinomenium acutum Rehder et Wils., Eugenia aromaticum, Rubus parvifolius L., Reynoutria elliptica, Coptis chinensis, Paeonia lactiflora Pall., Rheum undalatum, Paeonia suffruticosa, Oenothera odorata Jacq., Euphorbia pekinensis Rupr., and Nepeta cataria were selected based on spore germination inhibition assay. Further mycelial growth inhibition assay with economical and safety considerations led us to finally select Z. schinifolium (sancho) for control of F. graminearum. To produce antifungal sancho extract, methanol was suitable for extraction and subsequent fractionations of the extract showed that the water residue mainly had antifungal activity. The sancho extract and its fractions showed minor antibacterial activity against different pathogenic or food spoilage bacteria, but they did not show any harmful effects against young tomato plant by treatment of $1,000\;{\mu}g/ml$ in green chamber test. These results suggested that the extract of sancho has high potentials on control of a powdery mildew fungus, F. graminearum.