• The Korean Journal of Pesticide Science
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• v.5 no.1
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• pp.12-18
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• 2001

The effects of organophosphorus were examined with inhibition of the cholinesterase activity on tile chicken plasma in vivo and in vitro. The cholinesterase activity in chicken plasma determined by tile Ellman mettled was $23{\mu}mol$/min/g protein. After oral administration with 0.2 and 0.5 times of organophosphorus terbufos $LD_{50}$(1.81 mg/kg), cholinesterase activity were inhibited to 36% and 96% of control after 15min in vivo, respectively. After oral administration with 0.2 and 0.5 times of terbufos $LD_{50}$(1.81 mg/kg), then the recovery of cholinesterase activity followed to 99% and 56% of control after 11hr, respectively. Ki of phosphorodithioate and phosphorothioate with P=S was $74{\sim}322\;mole^{-1}min^{-1}$ in vitro. Ki of phosphate and phosphorothiolate with P=O was $13898{\sim}79610\;mole^{-1}min^{-1}$. Toxicology of organophosphorus with P=S was higher than that of organophosphorus with P=S by oxidation. $pI_{50}$ of phosphorodithioate and phosphorothioate with P=S was $21{\sim}102$ mg/L. $pI_{50}$ of phosphate and phosphorothiolate with P=O was $0.519{\sim}0.071$ mg/L. Enzyme-Inhibition method with cholinesterase was the rapid bioassay method to detect the organohpophorus pesticides in vitro.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.4
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• pp.321-329
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• 1993

The present study was conducted to elucidate the body modulating function of fermented seafood products. Angiotensin converting enzyme (ACE) acts in blood pressure regulation, converting angiotensin I to the potent vasoconstrictor angiotensin II and inactivating the vasodilator bradykinin to raise blood pressure. Salted and fermented anchovy which is one of the traditional fermented seafood in Korea was tested for inhibitory activity against ACE. ACE inhibitory activity of salted anchovy during the period of fermentation was increased with the elapse of fermentation days until fermentation of 60 days, but thereafter decreased inversely. When the fermented product was extracted with $50\%$ ethanol, the ACE inhibitory activity was the highest. And the ACE inhibitory activity was proportion to the content of $50\%$ ethanol soluble peptide-nitrogen of the fermented product. From the profiles of gel permeation chromatography on a Bio-Gel P-2 of $50\%$ ethanol soluble fraction obtained from salted and fermented anchovy fermented for 60 days at an ambient temperature, the higher activity fractions were C'($IC_{50}=97{\mu}g\;protein/ml$) and D'($IC_{50}=65{\mu}g\;protein/ml$). Amino acid analysis showed that the large quantify of threonine, glutamic acid, lysine for C' and serine, proline for D', respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.9
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• pp.46-54
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• 2003

The purpose of this study is to analyze the phenomena of the thermally-induced vibration for the flexible space structure due to abrupt change of radiation heating circumstance using the numerical analyze and experiment test. In order to verify this structure, numerical approaches on the simplified flexible tube were compared with experimental test results at the ground experimental facility. In this analyze, it was found that the thermal deformation occurs firstly due to fast radiation heating of flexible structure and then the thermally-induced vibration would be induced due to small periodic change of temperature. According to comparison of numerical and experimental results, in case of no tip mass, the first mode vibration by the numerical analyze was a.78Hz same as that of the experimental result. However in case of increase tip-masses of 8g, 16g, 50g and 100g, the first modes vibration theoretical analyze were 1.75Hz, I.3Hz, a.87Hz and 0.73Hz, in decrease trend respectively and those by experimental test were 2.34Hz, 1.5Hz, 0.78Hz and 0.78Hz in decrease trend respectively. Although using the simpled equation for the estimation, the estimation results were similar to experimental results.

• The Korean Journal of Mycology
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• v.23 no.1 s.72
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• pp.37-45
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• 1995

In order to study antibiotic activities of basidomycetes (mushroom), 68 species of mushroom were extracted with petroleum ether, 80% ethanol, and distilled water in that order. A total of 204 extracts were obtained. Antibiotic activities against Microsporum gypseum were observed from the petroleum ether extracts of Abortiporus DGU-L6 mushroom, and the water extracts of Clitogbe DGU-7 mushroom. Antibiotic activity against Aspergillus niger were observed from the 80% ethanol extracts of Cortinarius DGU-51 and Marasmminus DGU-L67 mushroom. The petroleum ether extracts of Hetero DGU-L25 mushroom showed various antibiotic activities, particularly strong activities against M. canis. and the minimum inhibitory concentration (MIC) was $40\;{\mu}g/ml$. The extracts also showed antibiotic activities against A. niger (KCTC 2025), A. niger (KCTC 2118), A. versicolor (KCTC 2120), A. flavus (KCTC 2117), M. gypsem, Pyricularia oryzae, and Trichopyto mentagrophytes, and MIC for each fungus was $600\;{\mu}g/ml,\;500\;{\mu}g/ml,\;800\;{\mu}g/ml,\;100\;{\mu}g/ml,\;600\;{\mu}g/ml,\;200\;{\mu}g/ml,\;and\;600\;{\mu}g/ml$, respectively.

• Microbiology and Biotechnology Letters
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• v.31 no.3
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• pp.211-215
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• 2003

When Saccharomyces cerevisiae MTY62, a high-RNA content yeast, was cultivated by fed-batch mode feeding molasses and com steep liquor, the cell density less than 45g-DCW/L and the RNA content less than 140mg/g-cell were obtained, indicating that unknown compounds inhibiting the cell growth and RNA accumulation are contained in the molasses. Therefore, in order to obtain higher levels of cell density and RNA content, $Ca^{++}$, $Cu^{++}$and $K^{+}$ ions in molasses were removed by pretreatments of molasses with various agents such as IonClear BigBead, $Na_2$$HPO_4$, $H_2$$SO_4$, citric acid, $K_2$$HPO_4$, and EDT A. Among them, IonClear BigBead, $Na_2$$HPO_4$, and EDTA gave the highest $Ca^{++}$ removal efficiency of about 60-90%. In the batch culture with pretreated molasses, the cell concentration of 18.6g-DCW/I and RNA concentration of 3127 mg/I, maximum specific growth rate of 0.459$h^{-1}$ , and specific consumption rate of reducing sugar of 1.28g-sugar/g-cell-h were obtained, which are about 10%, 17%,47%, and 36% higher levels, respectively, over the batch culture with untreated molasses.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.12
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• pp.900-906
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• 2011

To investigate concentration and sources of PCDD/Fs and Co-PCBs in sediments, total 52 sediment samples were measured at 17 sites in Geum River. As a result of analysis, total concentrations of PCDD/Fs and Co-PCBs were ranged from not detected (N.D.)~193.47 pg/g-d.w. (mean value: 84.52 pg/g-d.w) and 0.34~359.19 pg/g-d.w (mean value: 114.65 pg/g-d.w.) respectively. Also, toxic equivalent (TEQ) concentration of PCDD/Fs and Co-PCBs were ranged from N.D.~5.12 (mean value: 0.88) pg I-TEQ/g-d.w and N.D.~0.58 (mean value: 0.09) $WHO_{2005}$-TEQ pg/g-d.w. respectively. The upstream indicate the highest concentration and as it goes to the downstream, it has tendency to decrease. Higher chlorinated compounds were dominant in most of site which detected PCDD/Fs. Occurrence of Co-PCBs isomer patterns appear similar to each sampling site was found. The isomer patterns showed similar between sediment and PCB products. The principal component analysis also showed that the samples contained the characteristics of PCBs products.

• Journal of the Earthquake Engineering Society of Korea
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• v.10 no.2 s.48
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• pp.51-62
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• 2006

In the companion paper (I-Problem Statements of the Current Seismic Design Code), the current Korean seismic design code is required to be modified considering site characteristics in Korea for the reliable estimation of site amplification. In this paper, three site classification methods based on the mean shear wave velocity of the top 30m $V_{S30}$, fundamental site periods $(T_G)$ and bedrock depth were investigated and compared with each other to determine the best classification system. Not enough of a difference in the standard deviation of site coefficients $(F_a\;and\;F_v)$ to determine the best system, and neither is the difference between the average spectral accelerations and the design response spectrum of each system. However, the amplification range of RRS values based on $T_G$ were definitely concentrated on a narrow band than other classification system. It means that sites which have a similar behavior during earthquake will be classified as the same site category at the site classification system based on $T_G$. The regression curves between site coefficients and $T_G$ described the effect of soil non linearity well as the rock shaking intensity increases than the current method based on $V_{S30}$. Furthermore, it is unambiguous to determine sue category based on $T_G$ when the site investigation is performed to shallower depth less than 30m, whereas the current $V_{S30}$ is usually calculated fallaciously by extrapolating the $V_s$ of bedrock to 30m. From the results of this study, new site classification system based on $T_G$ was recommended for legions of shallow bedrock depth in Korea.

• Korean Journal of Logic
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• v.20 no.2
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• pp.241-271
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• 2017

Dialetheism is the view that there exists a true contradiction. This paper ventures to suggest that Priest's argument for Dialetheism from $G{\ddot{o}}del^{\prime}s$ theorem is unconvincing as the lesson of $G{\ddot{o}}del^{\prime}s$ proof (or Rosser's proof) is that any sufficiently strong theories of arithmetic cannot be both complete and consistent. In addition, a contradiction is derivable in Priest's inconsistent and complete arithmetic. An alternative argument for Dialetheism is given by applying $G{\ddot{o}}del$ sentence to the inconsistent and complete theory of arithmetic. We argue, however, that the alternative argument raises a circularity problem. In sum, $G{\ddot{o}}del^{\prime}s$ and its related theorem merely show the relation between a complete and a consistent theory. A contradiction derived by the application of $G{\ddot{o}}del$ sentence has the value of true sentences, i.e. the both-value, only under the inconsistent models for arithmetic. Without having the assumption of inconsistency or completeness, a true contradiction is not derivable from the application of $G{\ddot{o}}del$ sentence. Hence, $G{\ddot{o}}del^{\prime}s$ and its related theorem never can be a ground for Dialetheism.

• Korean Journal of Materials Research
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• v.11 no.8
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• pp.685-689
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• 2001

We carried out these experiments to examine the effects of element substitution of Co and La-Co for Sr-ferrite. The calcined properties of Co and La-Co element substitution were examined, and also the sintered magnetic properties were measured with the stoichiometric condition. The magnetic properties of $(La-Co)_{0.3}-SrM$ composition are as follows; $(M_s)$: 71.08 emu/g, $iH_c$: 4.38 kOe and $B_r$ : 4.18 kG, $iH_ c$ :4.35 kOe, $BH_{max}$: 4.3 MGOe. The $BH_{max}$ value was increased up to 10 % compared with conventional values. Our results imply that the magnetic properties of Sr-ferrite can be improved by the substitution of those elements.

• Journal of Convergence for Information Technology
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• v.10 no.12
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• pp.183-190
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• 2020

This study evaluated the possibility of Hoangtonogak Plus extracts as a bioactive ingredients for cosmetic products. Methanol(MN) and hot-water(WN) extracts were analysed by DPPH/ABTS radical scavenging activity, FRAP value for anti-oxidant activity, MTT assay for cell viability, inhibition of NO production and iNOS protein expression for anti-inflammatory effect, paper disc diffusion method for anti-microbial activity against Staphylococcus aureus, Staphylococcus epidermidis and Escherichia coli.. The contents of total polyphenol of MN and WN extracts were 2.92±0.01 mgGAE/g and 1.67±0.02 mgGAE/g, respectively. DPPH, ABTS and FRAP values of MN extracts were higher than WN at each concentration. No significant cytotoxicity was observed in RAW264.7 cells. Furthermore, NO production of MN and WN at 1 mg/mL concentration was measured as 11.69 μM, 20.4 μM, respectively. In addition, MN extracts showed anti-microbial effect only on S. epidermidis. Also MN extracts suppressed iNOS protein level in a concentration-dependent manner. According to our results, the MN extracts demonstrated its potential as a natural source of antioxidant with anti-microbial and anti-inflammatory properties.