• Korean Journal of Veterinary Research
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• v.26 no.1
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• pp.149-156
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• 1986

An experiment was carried out to measure the cellular immune response in the animals by sensitizing the animals with 2, 4-dinitrochlorobenzene(DNCB). The fowls could be sensitized with primary application of DNCB. The sensitizing and challenge dose was standardized. Heterophils were prominent in the early inflammatory response in the superficial and deep dermal regions with scattering of eosinophils. The histological response in the fowls was characteristic of a delayed hypersensitivity reaction.

• Journal of the Korean Applied Science and Technology
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• v.16 no.3
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• pp.199-203
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• 1999

The symmetric benzoxazolo carbocyanine is of industrial importance as green-sensitizing dye in the spectral sensitization of emulsion microcrystals in positive paper and negative film-making. The stability on the solvents of benzoxazolo carbocyanine dye was measured by UV-Vis spectrophotometer, and then all of solvents were stabilized sensitizer. The maximum absorption peak range in methanol, acetonitrile, acetone, DMF, dichloromethane, chloroform solvents was $501nm{\sim}511nm$. But it was identified that only methanol can be used to photographic emulsion. The photographic characteristics have contrast of 2.8, speed of 50-55$(lux{\cdot}sec)^{-1}$, fog of 0.07-0.08, respectively.

• Proceedings of the Korean Society of Potoscience Conference
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• 2006.06a
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• pp.28-28
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• 2006

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 1999.05a
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• pp.101-101
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• 1999

• Proceedings of the KSMRM Conference
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• 2004.09a
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• pp.40-40
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• 2004

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.2
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• pp.343-351
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• 1998

This paper was investigated degradation of the fracture toughness caused by sensitizing heat-treatment of the cryogenic structural material JN1 base metal using unloading compliance method reported as useful a method in evaluating the elastic-plastic fracture toughness at cryogenic temperature. The specimens used in this paper were 20% side-grooved 0.5T-CT specimens which were machined in the JN1 base metal. Also, to investigate cryogenic fracture toughness of the fusion line region in the JN1 GTA weldments, it was also used 20% side-grooved 0.5T-CT specimens that was machined fusion line to located in the middle of the specimen. The cryogenic fracture toughness values of the JN1 base metal were significantly decreased with increasing the time and temperature of the heat treatment. The fracture toughness value obtained from the fusion line specimen was invalid, but it was lower value than that of the JN1 base metal. Especially, this value was approximately equal with that obtained from the JN1 650.deg. C-5h heat-treated material.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.2
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• pp.311-320
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• 1998

The cryogenic fracture behaviors of austenitic stainless steel HN2 developed for nuclear fusion reactor were evaluated quantitatively by using the small punch(SP) test. The electrochemical polarization test was applied to study thermal aging degradation of HN2 steel. The X-ray diffraction(XRD) analysis was conducted to detect carbides and nitrides precipitated on the grain boundary of the heat treated HN2 steel. The mechanical properties of the HN2 steel significantly decreased with increasing time and temperature of heat treatment or with decreasing testing temperature. The integrated charge(Q) obtained from electrochemical polarization test showed a good correlation with the SP energy(ESP) obtained by means of SP tests. From the results observed in the x-ray diffraction and anodic polarization curve, it was known that the material the grain boundary. Combining SP test and electrochemical polarization test, it could be useful tools to non-destructively evaluate the cryogenic fracture behaviors and the aging degradation for cryogenic structural material.

• Corrosion Science and Technology
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• v.12 no.6
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• pp.265-273
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• 2013

Ti-stabilized 11 wt% Cr ferritic stainless steels (FSSs) for automotive exhaust systems have been experienced intergranular corrosion (IC) in some heat-affected zone (HAZ). The effects of sensitizing heat-treatment and silicon on IC were studied. Time-Temperature-Sensitization (TTS) curves showed that sensitization to IC was observed at the steels heat-treated at the temperature lower than $650^{\circ}C$ and that silicon improved IC resistance. The sensitization was explained by chromium depletion theory, where chromium is depleted by precipitation of chromium carbide during sensitizing heat-treatment. It was confirmed with the results from the analysis of precipitates as well as the thermodynamical prediction of stable phases. In addition, the role of silicon on IC was explained with the stabilization of grain boundary. In other words, silicon promoted the formation of the grain boundaries with low energy where precipitation was suppressed and consequently, the formation of Cr-depleted zone was retarded. The effect of silicon on the formation of grain boundaries with low energy was proved by the analysis of coincidence site lattice (CSL) grain boundary, which is a typical grain boundary with low energy.

• Corrosion Science and Technology
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• v.19 no.1
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• pp.37-42
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• 2020

Even though 304 low-carbon (304L) stainless steel was developed to enhance the resistance to intergranular corrosion and stress corrosion cracking, it is occasionally subject to degradation in harsh environments. The degree of sensitization (DOS) of 304L stainless steel was studied as a function of sensitization using a double-loop electrochemical potentiokinetic reactivation (DL-EPR) method. Sensitizing heat treatment was performed in an Ar atmosphere at 500℃, 600℃, and 700℃, with heat treatment times varying from 0 to 96 h. DOS was measured by the ratio of the peak current density value of the forward scan to that of the reverse scan. After the EPR experiment, the specimen surface was observed by scanning electron microscopy and energy dispersive spectroscopy. The DOS of the specimens heat-treated at 600℃ increased with heat treatment times up to 48 h and then decreased due to a self healing effect. The DOS was higher in specimens heat-treated at 600℃ than those at 500℃ or 700℃. Corrosion of the sensitized specimens occurred mainly at the δ-γ phase boundary. The corrosion morphology at the δ-γ phase boundary changed with sensitizing heat-treatment conditions due to differences in chromium activity in γ austenite and δ ferrite.

• Korean Journal of Food Science and Technology
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• v.36 no.3
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• pp.472-477
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• 2004

Hypoglycemie effect of Moutan Radicis Cortex (MRC) extract contained in Yukmijihuang-hwan was determined by investigating insulin-sensitizing and ${\alpha}-glucoamylase-suppressing$ actions. MRC was extracted with 70% ethanol, fractionated by XAD-4 column chromatography with mixture solvent of methanol and water, and utilized for hypoglycemic effect assay. Significant insulin sensitizing activities of MRC extracts were observed in 3T3-L1 adipocytes, giving MRC extracts with 1 ng/mL insulin reach glucose uptake level increased by 50 ng/mL of insulin alone. MRC methanol extracts of 20, 40, 60, and 80% suppressed ${\alpha}-glucoamylase$ activity in vitro. Peak serum glucose levels and area under curve were lower in Sprague Dawley male rats treated with MRC ethanol extract than those treated with cellulose in oral glucose tolerance test using 2 g dextrin/kg body weight. These data suggest MRC extracts contain effective insulin -sensitizing and ${\alpha}-glucoamylase-suppressing$ compounds for hypoglycemic activity.