• Journal of Korean Port Research
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• v.14 no.3
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• pp.373-378
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• 2000

Oil spill in sea water is the most frequent and significant problem of marine pollution. As an early detection sensor of the pollution, an activated carbon coated quartz crystal is prepared and examined for its performance of detection sensitivity and stability. Powdered activated carbon and phenol resin is coated on the surface of the sensor and the sensor is baked for an hour. Adsorption of acetone dissolved in water and salt water is measured using frequency shift of quartz crystal at different concentrations of solute material. The outcome indicates that the sensor preparation is adequate and the measurement of solute concentration is stable and sensitive enough to be implemented on the monitoring of solute concentration is stable and sensitive enough to be implemented in the monitoring of organic pollution of sea water.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.478-481
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• 2005

In this study optical sensing membrane was developed for the queantification of dissolved carbon dioxide in micro-bioreactor using an immobilized 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS). For the immobilization of HPTS sol-gel was synthesied by using 3-glycidoxypropyl-dimethoxymethylsiline and tetraethyl orthosilicate.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.170-170
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• 2005

• Journal of the Korean Applied Science and Technology
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• v.20 no.4
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• pp.366-371
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• 2003

In this paper, it was studied about the red-sensitive layer. UV-Vis data of the dye at monomeric and J-state were considered with respect to their performance(contrast, speed, density and fog) in photographic emulsion. The sensitizing effect of the dye is found to be strongly structure-dependent. Naphthctbiazolo carbocyanine dye can be used as red sensitizing dye for the spectral sensitization of photographic emulsion.

• Journal of Photoscience
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• v.5 no.1
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• pp.45-46
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• 1998

The green-sensitive silver halide emulsion layer has been studied UV-Vis absorption band of 9-methvl-5,5'-diphenyl-3,3'-bis(3-sulfopropyl)benzoxazolo carbocyanine triethyl ammonium salt in methanol solution and 10% methanol containing 10$^{-2}$ M KCl. the products were observed at 502nm and 540nm(J-band), respectively. The maximum spectral sensitivity of sensntizing silver halide emulsion showed at 546nm. In conclusion, benzoxazolo carbocyanine dye can be used as a green-sensitizing dye for the photographic emulsion.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.165-166
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• 2003

완전히 가수분해 된 폴리비닐알콜(PVA)은 에멜전 안정화와 계면활성이 약하다. $^{1)}$ 하지만 hydrophobically modified PVA는 높은 계면활성을 가지고 있을뿐더러 수용액에서 micelle을 형성할 수 있고 게다가 그의 수용액은 높은 viscosity, shear thinning, thixotropic, less salt sensitive 성질을 가지고 있어 enhanced oil recovery operations, drag reduction, flocculation, super absorbency, latex paints, hydraulic fluids, surface coatings등에 사용될 수 있다. $^{2.3)}$ (중략)

• Journal of Pharmaceutical Investigation
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• v.38 no.4
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• pp.229-234
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• 2008

In the present study, chitosan-glycerophosphate sodium salt solution as a thermosensitive system (TSS) was used to formulate a temperature-sensitive drug delivery system (TSDDS) containing acetaminophen (AAP). The optimized TSS was prepared by measuring gelation temperature, gelation time and rheological properties of TSS. The optimized gelation temperature and time of TSS were $36^{\circ}C$ and 100 seconds, respectively. The viscosity of TSS was also suitable for maintaining gel structure at $37.2^{\circ}C$. The release profiles of TSDDS in PBS/pH 7.4 with various apparatuses and mass loss of TSDDS were investigated. The time required to release 50% of AAP from TSDDS ($t_{50%}$) was 120 min with the formation of pore on the surfaces, which was 2 times longer than that from AAP-chitosan gel. In addition, TSDDS was degraded approximately 80% within 4 hr and then degraded slowly for 20 hrs. In conclusion, AAP-TSS (TSDDS) formulated in this study might be suitable for some specific uses such as subcutaneous injection and rectal formulation.

• Macromolecular Research
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• v.11 no.3
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• pp.189-193
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• 2003

pH- and temperature-sensitive bifunctional hydrogels composed of N-isopropylacrylamide (NiPAAm) and a sulfadimethoxine monomer (SDM) derived from sulfadimethoxine were prepared. These hydrogels exhibit simultaneous pH- and temperature-induced volume-phase transitions. The pH-induced volume-phase transition behavior is produced by the ionization/deionization of SDM and is very sharp. In the high pH region, the ionization of SDM induces swelling of the hydrogels. In the low pH region, the deionization of SDM induces deswelling of the hydrogels. The temperature-induced volume-phase transition behavior of the bifunctional hydrogels exhibits negative thermosensitivity because of the NiPAAm component. The hydrogels swell even at low pH as the temperature decreases. The hydrogels swell at low temperature and high pH, and deswell at high temperature and low pH. The volume of the hydrogels dependl on the balance of the swelling and deswelling produced by the two competing stimuli, pH and temperature.

• Journal of Applied Biological Chemistry
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• v.42 no.4
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• pp.169-174
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• 1999

Arabidopsis AHL gene contains 4 exons encoding a putative protein highly homologous to the yeast salt-sensitive enzyme HAL2, a 3'(2'),5'-bisphosphate nucleotidase involving in reductive sulfate assimilation. AHL cDNA complemented yeast met22 (hal2) mutant. AHL fusion protein expressed in E. coli exhibited $Mg^{2+}$-dependent, 3'-phosphoadenosine 5'-phosphate (PAP)-specific phosphatase activity. $Li^+,\;Na^+,\;K^+$ and $Ca^{2+}$ ions inhibit the enzyme activity by competing with $Mg^{2+}$ for the active site of the enzyme. The enzyme activity was also sensitive to ${\mu}M$ concentrations of toxic heavy metal ions such as $Cd^{2+},\;Cu^{2+}$ and $Zn^{2+}$, but was not recovered by addition of more $Mg^{2+}$ ions, suggesting that these ions inactivate the enzyme with a mechanism other than competition with $Mg^{2+}$ ions. Inhibition of the AHL enzyme activity may result in accumulation of PAP, which is highly toxic to the cell. Thus, the AHL enzyme could be one of the intial targets of heavy metal toxicity in plants.

• Macromolecular Research
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• v.16 no.2
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• pp.169-177
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• 2008

This paper reports a facile synthesis of new water-soluble poly(ethylene oxide) (PEO)-based amphiphilic block copolymers showing pH sensitive phase transition behaviors. The copolymers were prepared by atom transfer radical polymerization (ATRP) of methacrylamide type of monomers carrying a sulfonamide group using a PEO-based macroinitiator and a Cu(I)Br/$Me_6TREN$ catalytic system in aqueous media. The resulting polymers were characterized by a combination of $^1H$-NMR, size exclusion chromatography, and UV/Visible spectrophotometeric analysis. The micellization of the block copolymers as a drug-loading mechanism in aqueous media using fluorescein salt was examined as a function of pH. The stable micelle formation and its loading efficacy suggest that the block copolymers can be used as precursors for drug-nanocontainers.