• Journal of the Korean Applied Science and Technology
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• v.8 no.2
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• pp.153-159
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• 1991

The electrochemical oxidation of p-methoxyphenol and hydroquinone for wastewater treatment application was investigated on platinum anode. At the cyclic voltammetry, it was observed that nagative shift of peak potential of p-methoxyphenol and hydroqinone as the pH of electrolytes increases and the peak current showed higher at strong electrolytes than weak electrolytes. In the case of p-methoxyphenol, the optimum electrode potential of controlled potential electrolysis was observed at the potential region of 0.8-1.0 (V vs. SCE) and hydroquinone was showed at the potential of l.0(V vs. SCE). Specially the oxidation rate of p-methoxyphenol and hydroquinone was showed high value in the acid electrolytes.

• Proceedings of KOSOMES biannual meeting
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• 2005.05a
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• pp.161-165
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• 2005

Recently, it is on the increase interest for Al alloy with new material for ship application to substitute for FRP ship. The reason is thatAl alloy ship has beneficial characteristics such as high sea speed, increase of loadage and easy to recycle compared with FRP ship. In this paper, mechanical and electrochemical properties are investigated by slow strain rate test experiment in various applied potential condition. These results will provide as reference data to design ship by deciding optimum protection potential regard to hydrogen embrittlement and stress corrosion cracking. In general, Al and Al alloys are not corroded with forming film which has the corrosion resistance property in neutral solution. However, it was observed that formation and destruction of passive film by $Cl^-$ ion in sea water environment. At comparison of current density after 1200 sec in potentiostatic experiment, the current density in the potential range of -0.68 $\~$-1.5 V is shown low value. The low current density means protection potential range. Elongation in applied potential of 0 V was high. However, the corrosion protection application in this condition is impossible potential because the toughness is low value by decreasing strength by active dissolution reaction at parallel part of specimen. The film composed with $CaCO_3$ and $Mg(OH)_2$ has a corrosion resistance property. However, the uniform electrodeposition coating at below -1.6 V potential is not formed since the time to form the uniform electrodeposition coating is short. Therefore, it is concluded that mechanical property is poor because effect by hydrogen gas generation is larger than that of electrodeposition coating. It is concluded that the optimum protection potential range from comparison of_maxim urn tensile strength, elongation and time to fracture is -1.3$\~$0.7 V (SSCE).

• Biomolecules & Therapeutics
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• v.14 no.1
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• pp.25-29
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• 2006

We tested effects of bioactive lysophospholipids including lysophosphatidic acid (LPA), lysophosphatidylcholine (LPC), sphingosylphosphorylcholine (SPC), and sphingosine I-phosphate (S1P) on membrane potential in C6 glioma cells to understand action mechanism of the lysophospholipids. Membrane potential was estimated by measuring fluorescence change of DiBAC-loaded glioma cells. LPA largely increased membrane potential and the increase was gradually diminished. LPC also increased the membrane potential, however, the increase sustained. SPC induced smaller increase of membrane potential than LPC. SIP was not able to change the membrane potential. We tested effects of suramin and pertussis toxin on lysophospholipid-induced membrane potential increase. However, there wasn't any effect. The membrane potential increase was partially diminished in $Na^+$-free media, suggesting $Na^+$ influx as a component of membrane potential changes. Thus, involvement of $Na^+$ influx in the increase of membrane potential by lysophospholipids and independence of suramin-sensitive GPCRs and pertussis toxin-sensitive G proteins are found in this study.

• Journal of Sensor Science and Technology
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• v.16 no.2
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• pp.115-119
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• 2007

We report electrokinetic streaming potential detection in a microchannel. Streaming potential, one of the representative electrokinetic phenomena, becomes noticeable either when the channel size reduces or when the concentration of electrolyte reduces. We suggest a triangular-shaped microchannel to enhance streaming potential. The triangular-shaped microchannel shows better performance than the straight one in terms of streaming potential. Couple of possible methods to enhance streaming potential is also discussed. Moreover, this type of channel and phenomenon can be applied to biological sensor application and energy transduction.

• Biomolecules & Therapeutics
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• v.14 no.2
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• pp.110-113
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• 2006

We tested effect of sarcotride A, a bioactive cyclitol derivative from a marine sponge, on membrane potential in C6 glioma cells. Membrane potential was estimated by measuring fluorescence change of DiBAC-loaded glioma cells. Sarcotride A increased membrane potential in a concentration-dependent manner. We tested effects of pertussis toxin, U73122, EIPA, and $Na^+-free$ media on sarcotride A-induced increase of membrane potential to investigate involvement of G proteins, phospholipase C, $Na^+/H^+$ exchanger, and $Na^+$ channels. However, we were not able to observe any significant effect of those pharmacological inhibitors, excluding the involvement of the molecules as candidate targets or signaling molecules of sarcotride A-induced increase of membrane potential. Further investigation is necessary to elucidate action mechanism of sarcotride A.

• Journal of Ecology and Environment
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• v.38 no.1
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• pp.15-23
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• 2015

This study was conducted in an effort to provide important clues pertaining to the conservation and restoration of Aporia crataegi by identifying the spatial distribution characteristics of the current habitats, prospective habitats, and future habitats of A. crataegi in accordance with climate changes. To determine the distribution of A. crataegi, data from a total of 36 collecting points throughout South Korea, North Korea, China, Japan, Mongolia, and Russia are used. The spatial distributions of the data were examined through MaxEnt modeling. The distribution probability rates exceeded 75% at 18 locations among the 36 species occurrence locations, with Gangwon province showing the highest distribution probability in South Korea. The precision of the MaxEnt model was remarkably high, with an AUC value of 0.982. The variables that affect the potential distribution of A. crataegi by more than 10% are the degree of temperature seasonality, the amount of precipitation in the warmest quarter, the annual mean temperature, and the amount of precipitation in the driest month, in that order of importance. It was found that the future potential distribution area of A. crataegi continuously moves northward over time up to 2070s. In addition, the area of the potential distribution showing a habitable probability rate that exceeds 75% in northeast Asia was $28,492km^2$, where the area of potential distribution in the north part of Korean peninsula was $20.404km^2$ in size. Thus, it is anticipated that the most important future habitats of A. crataegi in the northeast Asia will be North and South Hamgyeong provinces and Ryanggang province near Mt. Baekdoosan in the northern area of the Korean peninsula.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.1
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• pp.40-48
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• 2017

In this study, we evaluated the nitrogen (N) mineralization potential and Nitrogen use efficiency (NUE) of oil-cake, compost, hairy vetch and barley, which are the most widely used organic amendments in South Korea. The N mineralization potential (No) for organic fertilizers treated soil was highest for the hairy vetch treatment with a value of $18.9mg\;N\;100\;g^{-1}$, followed by oil-cake, barley and compost. The amount of pure N mineralization potentials in hairy vetch, oil-cake, barley and compost treatments were 8.42, 7.62, 3.82 and $3.60mg\;N\;100\;g^{-1}$, respectively. The half-life ($t_{1/2}$) of organic N in soil amended with oil-cake fertilizer mineralized quickly in 17 days. While, $t_{1/2}$ values of organic N for the compost and barley treatments accounted to 44.4 and 44.1 days, respectively. Oil-cake was good in supplying nutrients to plants. Compost and barley inhibited plant growth in the beginning growth stage and this is attributed to N immobilization effect. The results of this study highlight that compost and barley could be used as potential slow release fertilizers in conventional agriculture.

• Journal of Applied Biological Chemistry
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• v.50 no.2
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• pp.97-100
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• 2007

• Proceedings of the Korean Nuclear Society Conference
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• 1999.10a
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• pp.366-366
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• 1999

• Proceedings of the Korean Society of Crop Science Conference
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• 2018.10a
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• pp.181-181
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• 2018