• Journal of the Korean Electrochemical Society
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• v.2 no.3
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• pp.123-129
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• 1999

Initial electrochemical characteristics of $LiCoO_2$ electrode for lithium ion battery with various content of super s black as conductive material were evaluated through the charge/discharge with the potential range of 4.3V to 2.0V versus $Li^+/Li^+$. The rate of C/4 and C/2 by the 3 electrode test cell composed with an electrolytic solution of 1 mol/l $LiPF_6/EC+DEC(1:3\;by\; weight)$. Lithium was used as reference electrode. High impedance charge behavior was observed at early stage of charge. In the case of $3\%w/w$ of super s black as conductive material, the specific resistance of the high impedance releasing was $3.82\;{\Omega}\;{\cdot}\;g-LiCoCo_2$ at the current density of $0.5 mA/cm^2$, which corresponds 7 times of the specific resistance of electrode $(0.728 g-LiCoO_2)$. At second charge, the specific resistance of the high impedance releasing was 63 mn · g-Lico02, which corresponds 12eio of the specific resistance of electrode and only $1.7\%$ of that of the first charge. The first charge and discharge specific capacities at C/4 rate were 160-161 and $153\~155mAh/g-LiCoO_2$, respectively, to lead $95.4\~96.4\%$ of coulombic efficiencies and ca. $6 mAh/g-LiCoO_2$ of initial irreversible specific capacity. Specific resistance at the end of charge and rest showed low value at content of super s black between 2 and $7\%w/w$, which agreed with characteristics of irreversible specific capacity. Capacity densities were reduced by the increasing the content of conductive material. They were 447 and 431mAh/ml when 2 and $2.9\%w/w$ of super s black were used, respectively, at the rate of C/4.

• Korean Journal of Ecology and Environment
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• v.47 no.4
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• pp.350-357
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• 2014

Harmful Algal Bloom Alert System (HABAS) for drinking water supply is require to fast and accurate count as system monitoring of cyanobacterium occurrence and inducing a response action. We measured correlation between colony size and cell number including genus Anabaena, Aphanizomenon, Microcystis, Oscillatoria which are targeted at HABAS, deducted from standard formula, and suggested calculation method from colony size to the number of cell. We collected cyanobacteria samples at Han River (Paldang reservoir), Nakdong River (Dalseong weir, Changnyeonghaman weir) and Geum River (Gobok reservoir) from August to October, 2013. Also, we studied correlation between colony size and cell number, and calculated regression equation. As a result of correlation of harmful cyanobacteria by genus, Anabaena spp. and Aphanizomenon spp. having trichome showed high correlation coefficients more than 0.93 and Microcystis spp. having colony showed correlation coefficient of 0.76. As a result of correlation of harmful cyanobacteria by species, Anabaena crassa, Aphanizomenon flos-aquae, A. issatschenkoi, Oscillatoria curviceps, O. mougeotii having trichome showed high correlation coefficients from 0.89 to 0.96, and Microcystis aeruginosa, M. wessenbergii, M. viridis having colony showed correlation coefficients from 0.76 to 0.88. Compared with other genus Microcystis relatively showed low correlation because even species and colony size are the same, cell density and cell size are different from Microcystis strains. In this study, using calculated regression might be fast and simple method of cell counting. From now on, we need to secure additional samples, and make a decision to study about other species.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.110-122
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• 2012

This study examined the benthic diatom community distribution, land cover/use and water quality in relation to stream shape complexity (SSC) in the Seom River watershed. SSC showed a significant relation to the riparian land cover/use pattern and also water quality variables of the studied streams. Streams with high stream shape complexity (HSC) appeared to have a high proportion of forest and farmland, while streams having a low stream shape complexity (LSC) appeared to have high proportion of city. Streams with lower SSC showed higher nutrients concentration in the stream waters. Benthic diatom species composition and dominant species appeared to be similar regardless of SSC differences among the studied streams, while the variation of diatom density was manifested with SSC. The relative abundance of dominant benthic diatoms varied with SSC. Saprophilic diatoms were dominant in the streams of LSC, while saproxenic diatoms were dominant in the streams of HSC. During the evaluation of biological water quality using the benthic diatom indices, Trophic Diatom Index (TDI) and Diatom Assemblage Index to organic water pollution (DAIpo), the streams of LSC generally showed poorer water quality than those of MSC (Middle stream shape complexity) and HSC. In particular, BOD, TP, and $PO_4$-P showed significant relationships with DAIpo. In conclusion, shape complexity of streams in the Seom River watershed showed a close relation with benthic diatom distribution. This relation seemed to primarily be resulted from the effect of proximate factors, such as water quality, which might be affected by the land use types determining the degree of SSC.

• The Korean Journal of Malacology
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• v.24 no.3
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• pp.215-228
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• 2008

This study was performed to find out the community structure of macrobenthos and the environmental factors around Munseom coastal water in Jeju Island from June to December, 2007. Mean temperature and mean salinity were $19.6^{\circ}C$ and 34.03 psu, indicating stable water masses. Concentrations of DO, COD and SS were as low as those in the standard sea-water-quality classes I. Chlorophyll a concentrations ranged from 0.40 to 1.09 mg/L (mean, 0.69 mg/L), and higher concentration was observed in December rather than in June due to a blooming in winter. The mean concentration (their ranges are in parentheses) of nitrate, phosphate, and silicate were 0.15 mg/L (0.073-0.264 mg/L), 0.01 mg/L (0.004-0.011 mg/L) and 0.23 mg/L (0.039-0.464 mg/L), respectively. The values were higher near the Munseom due to influxes from the land. Of the 112 species that were identified, 40 species (36.0%) were Mollusca; 33 (28.8%) were Cnidaria; 13 (11.7%) were Porifera; 8 (7.2%) were Arthropoda and 17 species (15.3%) were others including Echinodermata. Density and biomass were estimated to be 4,340 individual/$m^2$ and $53,107.8\;gwwt/m^2$ respectively. Anthozoa was the most dominant group in abundance ($2,132\;ind./m^2$) as well as in the number of species, whereas Cnidaria was predominant in biomass ($37,630.9\;gwwt/m^2$). The dominant species were Dendronephthya gigantea, Scleronephthya gracillimum, Anthoplexaura dimorpha, Dendronephthya castanea, Thecocarpus niger, Dendronephthya spinulosa, Dendronephthya putteri, and Acabaria bicolor in the depth of 10-30 m. The seasonal variations of the number of individual and biomass of Cnidaria and Mollusca were observed. There was a slow increment in June, a decrement in October, and a drastic increasing in December. The biodiversity, evenness and richness index in surveyed stations were 2.715-3.413 (H'), 0.758-0.851(E'), and 5.202-8.720 (R) respectively. The dominance index was the highest in station M2 and the lowest in station M1.

• Clean Technology
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• v.20 no.3
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• pp.232-240
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• 2014

The significance of thermoplastic polyolefin polypropylene (PP) lies in its potential to replace polyvinyl chloride (PVC), the most widely used material for automobile interiors (door trim, dash board), which discharges harmful compounds in certain conditions. Another benefit of PP (0.855 amorphous - 0.946 crystalline $g/cm^3$) is its low density compared to that of PVC ($1.1-1.45g/cm^3$), which reduces vehicle weight. Market demand for eco-friendly water-based adhesive/coating material is rising significantly as a substitute for solvent-based adhesive/coating material which emits VOC and causes harmful working conditions. Under such context, in this study, a series of eco-friendly waterborne polyurethane-urea primer (a paint product that allows finishing paint to adhere much better than if it were used alone) for hydrophobic PP were prepared from different mix of DMPA content, NCO/OH molar ratio, various wt% of silicone diol and various soft segment content, among which DMPA of 21 mole %, NCO/OH molar ratio of 1.2, modified silicone diol of 5 wt% and soft segment content of 73 wt% led to good adhesion strength. Additionally, the incorporation of optimum content of additives (0.5 wt% dispersing agent, 0.5 wt% levelling agent, 1.5 wt% antifoaming agent, 3.0 wt% matting agent) into the optimum waterborne polyurethane-urea also enabled good stability, levelling, antifoaming and non-glossy.

• Journal of the Speleological Society of Korea
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• no.63
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• pp.1-8
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• 2004

The non-magnetic materials with non-conductive showing high structure dispersity were developed on the base of natural quartz and lava-scoria which was collected from Je-ju island in Korea, and treated by methane-chemical technology those were obtained novel properties of magnetization through the analyzing. Depending on the processing conditions and subsequent applications the materials produced by strong methane-chemical reaction (MCR) in alcohol solution showed concurrently magnetic, dielectric and electrical properties. The obtained magnetic-electrical powders classified by aggregate complex of their features as segnetomagnetics, containing a dielectric material as a carrying nucleus, particularly the quartz on that surface one or more layers of different compounds were synthesized having thickness up to 10～50 nm and showing magnetic, electrical and other properties. It was confirmed in magnetizing process that powders of quartz and lava-scoria produced by MCR were better oil adsorbent as of oleophilic and floating matter on water surface although their specific gravities are comparably more than 1 in quartz or less than unity, as that of water, in lava-scoira. Therefore, it will be Possible and very useful to remove low density and light gravity oil spillage in difficult recovery from sea and inland water contamination spread on water surface, by marine accident and ship sinking accident occurring frequently in recent years, by way of magnetic adsorbent conveyer system in continuous, if it could be built up the mass Production system of water-floating magnetizable oleophilic adsorbent materials with use of iow cost and good Qualify lava-scoria spread on volcano district in Je-ju island. And, there will also be urgent advent of necessity with strong possibility to develop useful applications of various magnetic functional materials include oleophilic adsorbent for removal of sea oil-contaminants and maritime pollutants, and other kinds of various utilities in industrial applications and practical uses of novel functional materials in the fields of environments and health care applications with in deep expectation.

• Korean Journal of Plant Resources
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• v.9 no.3
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• pp.285-290
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• 1996

This experiment was conducted to investigate the variation of adhering primary and secondary rachis branches of panicle in three ecotypes at National Honam Agricultural Experiment Station in 1993. Three ecotypes. Odaebyeo and Sinunbongbyeo as early-maturing type, Cheongmyeongbyeo and Changanbyeo as medium, and Dongjinbyeo and Mangeumbyeo as late-maturing type were used. The treatment were 5 planting times from May 5 to 5 July by 15 day intervals. The number of primary rachis branch in early maturing type recorded high in between May 5 and 20 May as early transplanting. Medium and late-maturing type, however, was found to be have more primary rachis branches at the late time of June 20 transplanting than at the optimum transplanting of Honam area. The number of secondary rachis branch was high between June 5 and 20 June regardless ecotypes. The rate of secondary rachis branch per primary rachis branch was increased with later transplanting time up to June 5, but showed no differences onwards. The number of grain in primary and secondary rachis branches were low in transplanting time of May 5 regardless ecotype but high in late transplanting time by July 5. Densinty of seed sets was found to be higher in late transplanting than in early transplating;early-maturing type showed high in July 5 and 20 June in medium-late maturing type respectively.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.16 no.1
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• pp.1-13
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• 2011

The Yellow Sea Cold Water (YSCW) is formed by cold and dry wind in the previous winter, and is known to spread southward along the central trough of the Yellow Sea in summer. Water characteristics of the YSCW and its movement in the northern East China Sea (ECS) are investigated by analyzing CTD (conductivity-Temperature-Depth) data collected from summertime hydrographic surveys between 2003 and 2009. By water mass analysis, we newly define the North Western Cold Water (NWCW) as a cold water mass observed in the study area. It is characterized by temperature below $13.2^{\circ}C$, salinity of 32.6~33.7 psu, and density (${\sigma}_t$) of 24.7~25.5. The NWCW appears to flow southward at about a speed less than 2 cm/s according to the geostrophic calculation. The newly defined NWCW shows an interannual variation in the range of temperature and occupied area, which is in close relation with the sea surface temperature (SST) over the Yellow Sea and the East China Sea in the previous winter season. The winter SST is determined by winter air temperature, which shows a high correlation with the winter-mean Arctic Oscillation (AO) index. The negative winter-mean AO causes the low winter SST over the Yellow Sea and the East China Sea, resulting in the summertime expansion and lower temperature of the NWCW in the study area. This study shows a dynamic relation among the winter-mean AO index, SST, and NWCW, which helps to predict the movement of NWCW in the northern ECS in summer.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.2
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• pp.112-119
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• 2012

This study investigated the diel and tidal distributions of the two mysids, Archaeomysis kokuboi and Acanthomysis nakazatoi, in relation to their growth stages in the sandy surf zone of Yongil Bay, located on the southeastern part of Korean Peninsula. Sampling was conducted with a sledge net at every two hours for almost 24 hours at three sites: water edge, water surface and sand bottom both in 1-m deep water areas. The abundance of Archaeomysis kokuboi juveniles was too low to count both in day and night samples. While there was no difference in immature A. kokuboi abundance between day and night in the bottom or water edge, that at the water surface was significantly higher at night than daytime. The abundance of A. kokuboi adults, especially of males, in the bottom was significantly higher in daytime than night and no individuals appeared to the water surface either day or night. In comparison, the abundance of Acanthomysis nakazatoi juveniles between day and night did not differ significantly at all the three sites, with the highest number being distributed in the bottom. The abundance of immatures between day and night also did not differ significantly and no individuals appeared to the water surface either day or night. The abundance of A. nakazatoi adults, especially females, in the bottom was significantly higher at night than daytime and there was no significant difference in abundance between day and night in the other sites. There was also no significant difference in abundances of the two species between ebb and flood tides, except for A. kokuboi immatures which appeared significantly more during the ebb tides at the water surface. Overall, the distribution of the two sympatric species, A. kokuboi and A. nakazatoi, was not the same in the sandy surf zone. Its difference seems to depend on their stages of growth, and the change in their abundance may be influenced more by diurnal rhythms than tidal effects. The population density of A. nakazatoi in the sandy surf zone was much higher than that of A. kokuboi, and relatively higher densities in all growth stages of the former were found in the sandy bottom ranging from juveniles to adults. These results indicate that A. nakazatoi has exceedingly better ability of sand burrowing even from the juvenile stage, and thus is an ecologically better adapted species in the sandy surf zone than another sympatric species, A. kokuboi.

• Journal of Veterinary Clinics
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• v.22 no.4
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• pp.336-341
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• 2005

Anabolic steroid compounds are widely used for the increase of muscle mass, density of bone and athletic ability. The present study conducted to evaluate the effects of nandrolone decanoate (ND), one of the anabolic steroid compounds, on disuse muscle atrophy and healing process of bone in dogs. Twenty physically healthy dogs of both sexes were used in this experiment and divided into three groups: group A (control), group B (low dose M-1.5 mg/kg) and group C (high dose ND-7.5 mg/kg). One-mm strip of full thickness bone was excised from the radius below the pronator teres muscle for the artificial fracture and then the fractured ends were fixed in apposition with bone plate leaving 1mm gap, and finally immobilized externally by Robert John's bandage for 4 weeks. ND was administered intramuscularly once a week far 8 weeks. Body weight, muscle mass change and fracture gap of the bone were evaluated immediately after surgery, and 2, 4, and 8 weeks after surgery. The rates of muscle mass change 8 weeks after surgery were $-2.75\pm0.16\%,\;1.68\pm0.11\%\;and\;1.74\pm0.48\%$ in groups A, B and C, respectively. The significant increase (p<0.05) of muscle mass increments were found in the treated groups. The fibrous connective tissue layer in the fracture gaps of the treated groups increased more than the control, especially in the group C at 4th week. More dense fibrous connective tissue were found in the treated groups at 8th week. Collectively, our results suggested that ND was an effective anabolic agent for the immobilized disuse muscle and bone healing.