• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.6
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• pp.728-735
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• 1995

The peptidyl prolyl cis-trans isomerase(PPlase, EC 5.2.2.8) from Bacillus stearothermophilus SIC1 was extracted from the cells treated with by lysozyme. PPlase was purified from the cell extracts by heat treatment, ammonium sulfate precipitation, ion exchange chromatography and finally gel filtration (FPLC). The purity of purified the enzyme after Superose 12 column chromatography was examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE). The molecular weight of the purified PPlase was estimated as 18,000 by SDS-PAGE. The 39 amino acid residues from the N-terminus were determined by the protein sequencer. The enzyme showed the optimum pH at 8.0 and was stable at the range of pH 7.0 to 8.0. The enzyme was considerably stable after heat treatment at $60^{\circ}C$ for 30 minutes, and the enzyme was quite stable up to $65^{\circ}C$. The presence of the PPlase in the refolding solution accelerated the isomerization rate of the assay peptide.

• Analytical Science and Technology
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• v.13 no.1
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• pp.22-26
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• 2000

2-Hydroxybenzaldehyde-5-Nitro-pyridylhydrazone (2HB-5NPH) was synthesized and its application in the spectrophotometric determination of vanadium ion(IV) was studied in the presence of surfactant. The optimum conditions of pH, solvent effect, concentration of ligand and surfactant were evaluated. The procedure was applied to determination of vanadium (IV) in mixture sample and real sample with satisfactory results (recovery ${\geq}$ 97% ; relative standard deviation ${\leq}$ 3.0% in the concentration range of $0{\sim}1.5{\mu}g/mL$ ; detection limit, $0.02{\mu}g/mL$ in solution).

• Food Science of Animal Resources
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• v.21 no.3
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• pp.246-255
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• 2001

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of muscles extracted with distilled water, saline solution, SDS or Trition X-100 showed simular protein patterns between Hanwoo and Holstein meat, indicating that SDS-PAGE technique may not be useful for the identification between Hanwoo and Holstein meat. Lectine blot analysis of muscle extracted with distilled water demonstrated that Hanwoo and Holstein meat had similar affinities for concanavalin A (Con A), ricinus communis agglutinin (RCA-120), ulex europaeus agglutinin (UEA-1) or peanut agglutinin (PNA) lectins. However, approximately 32.1 kDa component of Hanwoo meat showed high affinity for dolichos biflorus agglutinin (DBA) lectin. On the contrary, high molecular weight components of Holstein meat had the specific affinity for wheat germ agglutinin (WGA) lectin. Hanwoo meat-specific components were observed by lectin staining of heat-denatured meat at 100$^{\circ}C$ for 30 sec. Also, the component of heat-denatured meat at 100$^{\circ}C$ for 30 sec, which was slightly smaller than Hanwoo meat-specific component, was concentrated specifically in Holstein meat.

• Bulletin of the Korean Chemical Society
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• v.25 no.3
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• pp.345-346
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• 2004

• Applied Biological Chemistry
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• v.28 no.2
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• pp.88-91
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• 1985

For the systematic investigation of biochemical characteristics of Korean ginseng protein, protein fractions were analyzed by the techniques of sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. The effect of pH and various salts on extractibility of ginseng protein were determined while the amino acid composition was studied by amino acid autoanalyzer. The protein was consisted of 66.08% of albumin and 20.51% of glutelin. Extractability of ginseng protein was the lowest in pH 3.0 and the highest in $pH\;6.0{\sim}8.0$. Among the neutral salts solution, $0.4M\;Na_2CO_3$ showed maximum extractability while $1.0M\;MgSO_4$ solution showed the least extractability. Resonable precipitation was obtained by 40% of acetone and ammonium sulfate. It has been shown by SDS polyacrylamide gel electrophoresis that the soluble protein had 11 bands. The molecular weight for the main protein of the soluble protein wasestimated to be 43,000. In amino acid composition of water extracted protein, arginine content was the highest 47.17% while on the contray, proline and cystine contents were very low.

• Korean Journal Plant Pathology
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• v.11 no.4
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• pp.312-317
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• 1995

The polygalacturonase (PG) production in rotten apples by Botryosphaeria dothidea was purified by using gel filtration and ion exchange column chromatography, and the biochemical characters of PG were investigated. The purified PG appeared as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with approximate molecular weight of 49 kilodalton (kDa). The molecular weight was equal to the native molecular weight estimated by gel filtration. The Km and Vmax values of PG were 0.51 mg/ml and 90.9 $\mu$M/min/ml, respectively. Optimum pH was 4.0~5.0, and the PG activity was stable from pH 5.0~10.0. Optimum temperature of the enzyme activity was 4$0^{\circ}C$. The PG activity was relatively stable at 2$0^{\circ}C$, but it was reduced 45% at 4$0^{\circ}C$ and completely inactivated at 8$0^{\circ}C$. The PG activity was considerably inhibited by Cu2+, Zn2+, SDS and EDTA, whereas it was not effected by Ca2+, K+, Mg2+ or Na+ ions.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.5
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• pp.289-295
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• 2010

In this study, the enhancement of the thermal conductivity of water in the presence of multi-walled carbon nanotubes, MWCNT, was investigated. Sodium Dodecyl Sulfate, SDS, and Polyvinylpyrrolidone, PVP, were employed as the dispersant. SDS or PVP was added in pure water. And then, MWCNT of 0.0005, 0.001, 0.002, 0.003, 0.004, 0.005, 0.01, and 0.02 vol% was dispersed respectively. The thermal conductivity and the viscosity were measured with a transient hot-wire instrument built for this study and the DV II+ Pro viscometer. The results showed that PVP had good thermal conductivity at 300 wt% and this was better than that of SDS 100 wt%, also, the viscosity of nano fluid added PVP rapidly increased until 0.02 vol%.

• Journal of the Semiconductor & Display Technology
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• v.10 no.2
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• pp.91-95
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• 2011

Ni-CNT(carbon nanotubes) composite coating is often used for the surface treatment of electronic/mechanical devices to improve the properties of the exisiting Ni electroplating. For this, the dispersion of CNT particle is a critical process. In this study, ball milling and additive called sodium dodecyl sulfate(SDS) are employed for dispersion. Electroplated Ni-CNT films were examined by SEM-EDX, AES, microhardness tester, 4-point probe and contact angle measurement to find the optimum dispersion conditions. Ni-CNT coatings formed by ball milling for 9 hrs and with addition of SDS 12 times of CNT contents showed the highest hardness, reasonable resistivity and non-stick characteristics.

• Journal of the Korean Electrochemical Society
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• v.2 no.2
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• pp.66-69
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• 1999

A large number of works have been Performed to understand the electrochemical growth of Polypynole on conducting substrates in aqueous as well as in nonaqueous solutions. Recently most researches with Polypyrrole have tended to be directed toward technological applications, but many fundamental physical and chemical properties of Polypyrrole remain unknown. In Particular, microrheological Property of polypyrrole has been largely neglected until the advanced electrochemical quartz crystal microbalance technique was introduced recently. To study anion effects on microrheolosical Property of Polypyrrole, we investigated changes in viscoelasticity of Polypyrrole during electrochemical growth in neutral aqueous solutions by means of in siか electrochemical quartz crystal oscillator method. The results showed that the films of Polypyrrole synthesized in $KPF_6\;and\;KCIO_4$ were more viscoelastic than the ones in $KCI,\;KNO_3,\;KBr,\;KBF_4,\;K_2SO_4$, sodium tosylate (NaOTs), and sodium dodecyl sulfate (SDS). The growth rate of Polypyrrole in SDS was faster than that in the others utilized. Polypyrroles synthesized in buffered neutral solutions were more elastic than those in unbuffered neutral solutions.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.2
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• pp.101-105
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• 2010

We fabricated FEDs(Filed emission devices) based on ZnO nanowires. The ZnO nanowires were synthesized on Au thin films by hydrothermal method at the temperature of 90[$^{\circ}C$] on hot plate. In order to form tips of the ZnO nanowire, SDS(Sodium Dodecyl Sulfate) was mixed in O.05-0.3[wt%] solution as capping material. After 2 hour growth, we obtained nanowires of chain form The high-purity nanowires showed sharp tip geometry with a wurtzite structure. The field emission properties of the ZnO nanowires were investigated in high vacuum chamber. The turn-on field for the ZnO nanowires was found to be about 4.1[V/${\mu}m$] at a current density of 0.1[${\mu}A/cm^2$].