• Bulletin of the Korean Chemical Society
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• v.32 no.11
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• pp.3959-3962
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• 2011

A simple propargylamide-fuctionalized chemodosimeter was prepared for the ratiometric fluorescence detection of mercuric ions in HEPES buffer. The chemodosimeter exhibited $Hg^{2+}$-induced propargyl amide-tooxazole transformation, with a significant accompanying ratiometric change in fluorescence. It afforded high selectivity for mercuric ion detection without any competitive inhibition by common alkali, alkaline earth, or other transition metal ions. The probe showed a $17{\times}10^{-6}M$ detection limit for $Hg^{2+}$ ions and potential applicability for detecting aqueous $Hg^{2+}$ ions.

• Journal of Life Science
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• v.11 no.5
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• pp.457-463
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• 2001

A bacterial strain SC-22 which produced alkaline lipase was isolated from salf-fermented shrimps. Strains SC-22 was identified as Staphylococcus xylosus. An alkaline lipase excreted by Staphylococcus xylosus SC-22 was purified by ammonium sulfate predipitation and column chromatography on Sephadex G-100 and DEAE-Sephace. The specific activity of purified lipase was 756U/mg of protein with 17.2% yield. The approximate molecular weight of the purified enzyme was 47 kDa. The partially purified lipase preparation had and optimum temperature of 4$0^{\circ}C$, an optimum pH of 8.0, and a stable of 5~10. Lipase activities were enhanced by salt ions such as $Ca^{2+}$, $Mg^{2+}$,N $a^{2+}$ while inhibited remarkably by heavy metal ions, C $u^{2+}$ and P $b^{2+}$.EX> 2+/.

• Journal of the Korean Ceramic Society
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• v.48 no.3
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• pp.222-227
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• 2011

The hexavalent chromium ions in wastewater are highly toxic chemicals even at low concentrations. It causes serious diseases, such as cancer, skin disease, digestive trouble et. al. In this study, $Cr^{6+}$ ions were removed by using borosilicate glasses. Various glasses system with different compositions were prepared and then reacted in a solution contaning $Cr^{6+}$ ions. After the reaction, the concentration of the $Cr^{6+}$ ions remained in the solution was measured by ICP-OES. The reacted surface of the glasses was also analyzed by using a XRD, SEM, and EDS. When $Na_2O-RO-SiO_2-B_2O_3$ (RO=MgO, CaO, SrO, BaO) glasses were reacted with a solution containing $Cr^{6+}$ ions, the optimum removal efficiency of $Cr^{6+}$ ions was observed in the BaO glass. $Ba^{2+}$ ions leached out of these glasses combine with $Cr^{6+}$ ions in a solution to form $BaCrO_4$ crystals on the glass surface. In this manner, the $Cr^{6+}$ ions can be removed from the solution. It is conceivable that $Ba^{2+}$ ions are reacted with $Cr^{6+}$ ions in a solution immedeately after leaching out of the glasses. The pH of the solution for optimum removal of $Cr^{6+}$ ions were 3.0~5.0.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.E1
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• pp.29-39
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• 2003

The 10-day interval basis measurements of precipitation samples at Yangyang, the rural and coastal area on the eastern coast of the Korea peninsula were accomplished for understanding the precipitation chemistry and the temporal variations of major ions September 1991 to February 1997. The precipitation was slightly acidic, and 37% of the samples in winter were pH less than 4.5. The concentrations of cations were found on the order $Na^+\;>\;{NH_4}^+\;>\;Ca^{2+}\;>\;Mg^{2+}\;>\;K^+$ and those of anions followed the pattern $Cl^-\;>\;{SO_4}^{2-}\;>\;{NO_3}^-$. Neglecting sea salt components, the major ions controlling precipitation chemistry were nss-${SO_4}^{2-}$ and ${NO_3}^-$ in anion and ${NH_4}^+$ and nss-$Ca^{2+}$ in cation. Concentrations of these ions were lower than those measured at urban sites in Korea, but were higher than those measured in Japan. Most of nss-${SO_4}^{2-}$ and ${NO_3}^-$ were neutralized by ammonia and calcium species, especially alkaline soil particles in spring and ammonia gas in other seasons. Considering also the annual value of ［nss -${SO_4}^{2-}$］/［${NO_3}^-$］ ratio of 2.62 and the neutralizing factors, ammonium sulphate compounds were dominant. Annual mean concentrations of these ions showed relatively small fluctuations, while larger seasonal variations were observed with higher levels in spring and winter. Precipitation amount, influence extent of acidic gases and alkaline particles long-range transported from China continent, and energy consumption pattern in each season might be able to explain this seasonal trend.sonal trend.

• The Journal of the Acoustical Society of Korea
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• v.29 no.2
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• pp.111-117
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• 2010

Sonoluminescence (SL) is the light emitting phenomenon accompanied with ultrasonic cavitation in liquid. It attracts many interests because physics behind it remains uncertain and few applications have appeared. It has been known that the color of SL changes in solutions which include metallic ions. In the present work, colors of SL in alkali metallic and alkaline earth metallic ions were considered. RGB component was used to analyze the color of SL. By using RGB component, it was found that color of SL in metallic solution can be resolved into color of SL in pure water and flame color of metal which is different from high intensity color of line spectrum of alkaline earth metal. From this result, influence of metallic ion on SL and the temperature on violent collapsing of cavitation bubble was discussed.

• Microbiology and Biotechnology Letters
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• v.24 no.3
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• pp.316-320
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• 1996

An alkaline proteinase produced by Yarrowia lipolytica TH65 was purified by 40-65% ammonium sulfate fractionation, DEAE-cellulose chromatography, and gel filtration with Sephadex G-100 and Sephadex G-75. The purified enzyme was shown as a single band on SDS-PAGE, and its molecular weight 31,500. Optimum temperature and pH were 40$\circ$C and 8.5-9.0, respectively, and the enzyme was stable below 40$\circ$C and in the pH range of 6-8. The enzyme was strongly inhibited by divalent ions, completely by PMSF, and partially by EDTA, EGTA, and phenanthroline. But the inhibitory effect in the presence of EDTA, EGTA and phenanthroline could be reversed by addition of Ca$^{2+}$. Thus, these results indicated that the purified enzyme was an alkaline serine proteinase (E.C. 3.4.21.14).

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.98.1-98.1
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• 2011

We present here an isothermal, one-dimensional, steady-state model for a solid alkaline fuel cell (SAFC) with an anion exchange membrane. The conducting ions now move from the cathode to the anode in SAFC. The water is produced at the anode and is also a stoichiometric reactant at the cathode as well as hydrogen and oxygen. In the present model, a net-water-per-proton flux ratio can be predicted and the water transport in the SAFC is explained for various operating conditions.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.11 no.1
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• pp.32-55
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• 1975

The ammonium salt of N-Nitrosophenylhydroxiamine, namely Cupferron, is a well-known analytical reagent which precipitates a great number of metal ions in acid medium. Various structures of electrode reduction for N-Nitrosophenylhydroxiamine have been suggested in acid and alkaline media by many researchers, but not in neutral medium. So the mechanism of electrode reaction of Cupferron was investigated by both chronopotentiometric and polarographic methods. It was estimated that the reduction of Cupferron occurs in a three-step mechanism through which a chemical step is interposed between two charge transfer, the ECE (charge transfer-chemical reaction-charge transfer) mechanism, over a range of neutral and alkaline media. The chemical reaction of the process was assumed to be acid-base catalyzed from the fact that kapp (over all rate constant) of chemical reaction is pH dependent.

• Journal of Microbiology and Biotechnology
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• v.25 no.6
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• pp.845-855
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• 2015

The present study describes the gene cloning and high-level expression of an alkaline and thermostable lipase gene from Trichosporon coremiiforme V3. Nucleotide analysis revealed that this lipase gene has an open reading frame of 1,692 bp without any introns, encoding a protein of 563 amino acid residues. The lipase gene without its signal sequence was cloned into plasmid pPICZαA and overexpressed in Pichia pastoris X33. The maximum lipase activity of recombinant lipase was 5,000 U/ml, which was obtained in fed-batch cultivation after 168 h induction with methanol in a 50 L bioreactor. The purified lipase showed high temperature tolerance, and being stable at 60℃ and kept 45% enzyme activity after 1 h incubation at 70℃. The stability, effects of metal ions and other reagents were also determined. The chain length specificity of the recombinant lipase showed high activity toward triolein (C18:1) and tripalmitin (C16:0).

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.3
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• pp.66-73
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• 2003

Alkaline cellulolytic enzymes are prepared from Coprinus cinereus 2249. Recovery method of enzyme protein from cultured medium and effect factors on enzyme activity of protein were investigated. The results could summarized as follows, \circled1 Amount of enzyme protein from cultured medium was highest in incubation with shaking and addition of skim milk. \circled2 Protein from cultured medium was alkaline enzymatic protein which shows the highest activity at pH 9.0. \circled3 The most effective recovery method of enzyme protein was the precipitation of protein by addition of cultured medium of protein in ethanol. \circled4 The enzyme activity was enhanced by tween-80 and decreased with $Al_2(SO_4)_3$, $H_2O_2$et al, and was little changed with metal ions except $Hg^{++}$.