• Journal of the Korean Society for Heat Treatment
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• v.6 no.1
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• pp.26-36
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• 1993

In this study, the ausformed martensite and marformed martensite obtained from austenite with various deformation degrees in Fe-31% Ni-0.2%C alloy were transformed to revesed austenite at $510^{\circ}C$ by cyclic reverse martensite transformation. The effect of prior deformation, the rapid heating rate of reversion and number of cyclic transformation on the microstructure, mechanical properties of reversed austenite were investigated. The reverse austenite transformation is accomplised by the mechanism of shear type transformation. The structure of reversed austenite formed from ausformed martensite and marformed martensite with high deformation degrees is a fine structure of nearly equiaed grain containg a high density of dislocation tangles and was largely affected by the prior deformation applied before reversal transformation. The strength of reversed austenite is more increased with of cyclic transformation especially it is strength at the first cyclic transformation. The yield stress of revesed austenite of ausformed martensite is lower than that of marformed martensite.

• Journal of Food Hygiene and Safety
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• v.12 no.3
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• pp.217-227
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• 1997

These experiments were performed to investigate the safety of the three medicinal herbs- Curcuma longa Linne, Paeonia japonica Miyabe, Scutellaria baikalensis George-irradiated with gamma rays in respect of genotoxicity. The methanol-soluble and water-soluble fractions of the methanol-water extracts of the 10 kGy gamma-irradiated herbs were examined in two short-term in vitro tests : (1) Salmonella typhimurium reversion assay (Ames test) in strain TA 98, TA 100 and TA 012 (2) Micronucleus test in cultured Chinese hamster ovary (CHO) cells. No mutagenicity was detected in the assays with or without metabolic activation. From these results, the safety of the herbs irradiated with gamma rays at practical doses could be revealed in further tests of genotoxicity in vivo, chronic and reproductive toxiceity.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.10a
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• pp.180-180
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• 2001

The mutagenic potency of a new antibiotics, IDC- 7181, was evaluated using the mutagenicity tests including Ames, chromosome aberration and micronucleus tests. In bacterial reversion assay, IDC-7181 did not show any mutagenic response in the absence or presence of S9 mixture with Salmonella typhimurium TA98, TAlOO, TA1535 and TA1537 and E. coli WP2uvrA-(100, 50, 25, 12.5 and 6.25 $\mu\textrm{g}$/plate).(omitted)

• Journal of Food Hygiene and Safety
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• v.9 no.2
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• pp.67-74
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• 1994

This study was aimed to find out the comparative effects between non-irradiated, and 5kGy-10kGy of gamma-irradiated Panax Ginseng Radix powder on the genotoxicity for identification of possibility of DNA damage causing cancer. Four different short-term mutagenicity tests were used: (1) Salmonella typhimurium reversion assay (Ames test) (2) Chromosome aberration test in cultured Chinese hamster lung (CHL) fibroblast cells. (3) Micronucleus test in ddY mouse (4) Somatic mutation and recombination test in the wing cells of Drosophila melanogaster.Gamma-irradiated Panax Ginseng Radix powder revealed negative results in these four mutagenicity tests. This means gamma-irradiated ginseng could be safe on the genotoxic point of view.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1227-1236
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• 2001

Genotoxicological safety on 10 kGy-gamma irradiated vegetable juices such as Oenanthstolonifera DC., Daucus carota L., Brassica oleracea var. acephala and Angelica keiskei was determined by the Salmonella typhmurium reversion assay, the SOS Chromotest using in Escherichia cloi PQ37 and chromosome aberration test in cultured Chinese hamster lung (CHL) fibroblast cells. Vegetable juices exposed to 10 kGy-gamma ray revealed negative results in these three in vitro mutagenetic tests.

• 유공압시스템학회:학술대회논문집
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• 2010.06a
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• pp.116-125
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• 2010

In this study, a novel hydraulic energy-regenerative system was presented from its proposal through its modeling to its control. The system was based on a closed-loop hydrostatic transmission and used a hydraulic accumulator as the energy storage system in a novel configuration to recover the kinetic energy without any reversion of the fluid flow. The displacement variation in the secondary unit was reduced, which widened the uses of several types of hydraulic pump/motors for the secondary unit. The proposed system was modeled based on its physical attributes. Simulation and experiments were performed to evaluate the validity of the employed mathematical model and the energy recovery potential of the system. The experimental results indicated that the round trip recovery efficiency varied from 22% to 59% for the test bench.

• KSBB Journal
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• v.5 no.2
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• pp.125-131
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• 1990

Microbial production of L-phenylalanine using Corynebacterium glutamicum ATCC 21674, a tyrosine auxotroph resistant to aromatic amino acid analogues, has been studied and kinetic analysis was performed. Even though the strain was reported as a tyrosine auxotroph, it produced tyrosine and was able to grow on the minimal medium where no tyrosine was present. The average specific growth rate at the exponential growth phase was 0.087 hr-1. There was a dissociation of growth from the formation of the product. Linear correlation between biomass production and total CO2 production was obtained. The relationship between CO2 evolution rate and sugar consumption rate was also found to be linear.

• Bulletin of the Korean Chemical Society
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• v.28 no.6
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• pp.983-989
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• 2007

Azobenzene-cored dendrons having the photoisomerizable azobenzene core and terminal vinyl groups have been prepared. Absorption bands of azobenzene-cored dendrons are similar except more intense 280 nm band in higher generation azobenzene dendron. All three azobenzene-cored dendrons show reversible photoisomerization similar to simple azobenzene, irrespective of the generation of dendron. On 350 nm irradiation, absorption band around 344 nm decreases and 436 nm band increases. Photoisomerization reactions are very fast for all three azobenzene-cored dendron and the reaction efficiency is dependent of its generation and solvent. In the dark, slow thermal reversion to original absorption spectrum is observed.

• Korean Journal of Microbiology
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• v.21 no.4
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• pp.213-220
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• 1983

Conditions for isolation of protoplasts from conidiospores of Trichoderma koningii ATCC 26113 were tested. Maximum production of conidial protoplasts was obtained by preincubation of conidiospores on liquid minimal medium for 8 1/2 hrs. and by reaction with cell wall lytic enzyme for 3 hrs. Among effective cell wall lytic enzymes (Driselase, p-Glucuronidase, Novozyme and Zymolyase), Driselase was the most effective one on the production of conidial protoplasts. The production of conidial protoplasts was also enhanced by addition of 2-Deoxy-D-Glucose $(25{\mu}g/ml)$ into liquid minimal medium. Over 70% of the initial swollen conidia, preincubated in liquid minimal medium supplemented with 2-Deoxy-D-Glucose $(25{\mu}g/ml)$, were converted to protoplasts by incubation with 2% (w/v) commercial lytic enzyme Driselase at $28^{\circ}C$ for 3 hrs. The reversion frequency of the conidial protoplasts was about 30 times (25-50%) higher than that of mycelial protoplasts (0.6-1.3%).

• Biomolecules & Therapeutics
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• v.8 no.3
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• pp.248-254
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• 2000

(R)-JG-381, a R form of alkylglycidic acid derivative, was examined for mutagenicity in the reverse mutation test on bacteria, chromosomal aberration test on cultured mammalian cells and micronucleus test in mice. In the reverse mutation test on bacteria using Salmonella typhimurium strain TA98, TA100, TA102, TA1535, TA1537 with or without a metabolic activation system (S9 mix), (R)-JG-381 did not affect the revertant colonies but significantly increased revertant colonies in one test strain, TA98, compared with the vehicle control. In the chromosomal aberration (CA) test using cultured Chinese Hamster Lung fibroblast(CHL) cells, the number of aberrant cells was clot increased in the presence or absence of 59 mix at concentration of the (R)-JG-381 0.025 $\mu$l/m1 to 0.1 $\mu$l/m1, compared with vehicle control. In the micronucleus (MN) test, micronucleated polychromatic erythrocytes in the (R)-JG-381-treated mice were not different from those of the vehicle-treated mice.