• Journal of Life Science
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• v.19 no.11
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• pp.1672-1678
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• 2009

The purified antifungal substances produced by Bacillus amyloliquefaciens IUB158-03 was positive to ninhydrin but negative to aniline, suggesting that the antifungal substance could be a peptide. FAB-MS, UV adsorption spectrum, and amino acid composition analysis revealed that the molecular weight of the antifungal substance was 1042 and that maximal adsorption was at 220 nm and 277 nm. The antifungal substance was composed of $Asn_3$, $Gln_2$, $Ser_1$, $Gly_1$, and $Tyr_1$. The composition and structural characteristics of antifungal substance were analysed by $^1H$-NMR spectrum, $^1H$-COSY, HMQC, which revealed that the compound belongs to the iturin A family. Temperature and pH had little effect on the stability of the antifungal substance in the ranges of $-70{\sim}121^{\circ}C$ and pH 6.0~10.0, respectively. It showed strong antibiotic activity against fungi. An in vitro cytotoxicity test using NIH3T3 cell showed that the antifungal substance does not have cytotoxicity. The number of circulating leukocytes and the hematobiological analysis of the mice administered with the antifungal substances was similar to those of the control group, indicating no cytotoxicity in vivo. Therefore, the antifungal substances extracted from culture broth of Bacillus amyloliquefaciens IUB158-03 have future potential as biocontrol agents against plant diseases caused by fungi.

• Fire Science and Engineering
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• v.33 no.4
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• pp.16-27
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• 2019

A burning test was conducted on the smoke and combustion gases generated from cypress wood treated with sodium silicate, 3-aminopropyltrimethoxysilane sol, 3-(2-aminoethylamino)propylmethyldimethoxysilane sol, and 3-(2-aminoethylamino) propyltrimethoxysilane sol. The silicone compound sol was applied to each of the cypress wood specimens three times with a brush. The smoke and combustion generation gas were analyzed using a cone calorimeter (ISO 5660-1) and the smoke was also evaluated by applying new smoke risk assessment method. The smoke performance index (SPI) of the cypress treated with silicone compound increased 1.66 to 8.42 times and the smoke growth index (SGI) was 11.8 to 88.2%, respectively. The smoke intensity (SI) is expected to be 1.0~50.5% lower than that of the base specimens, resulting in lower smoke and fire hazards. The third maximum carbon monoxide (CO_peak) concentration of the specimens treated with silicone compounds was 22.5~33.3% lower than that of the base specimens. On the other hand, it produced potentially fatal toxicity that was 1.48~1.72 times higher than the US Occupational Safety and Health Administration (OSHA) acceptance standard (PEL). Cypress wood itself produced a high carbon monoxide concentration, but the silicon compound played a role in reducing this level.

• Journal of Ginseng Research
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• v.23 no.3 s.55
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• pp.182-189
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• 1999

For the determination of anti oxidative effects of Korean red ginseng extracts, 100 mg/kg body weight of paraquat(1,1-dimethyl-4,4-bipyrimidinium dichloride) was injected to peritoneal cavity of 6 weeks 23-27 g of ICR mail mice which were pretreated with 200 mg/kg body weight of korean red ginseng extracts(total saponin, water extracts, alcohol extracts, lipophilic extracts) and ascorbic acid for 5 days. Most of mice died of paraquat toxicity within 4 days except only $30\%$ of ascorbic acid group. The hepatic total-SOD activity in liver was highest in ascorbic acid group and lipophilic ginseng extracts group next (p<0.0l). The level of hepatic hydroperoxide was lowest in the order of in alcohol extracts group, lipophilic extracts group and ascorbic acid group (p<0.0l). The highest catalase activity was induced by ascorbic acid followed by water extracts and lipophillic extracts (p<0.01). Finally, the lipid peroxidation level (malondialdehyde:MDA) was the lowest in water extracts group and ascorbic acid next (p<0.01). The highest MDA level was appeared in praquat group and next total saponin group next. In conclusion, the order of effectiveness of antioxidants was found to be ginseng water extracts> ascorbic acid> lipophillic extracts> other ginseng extracts. It was also found that any predominant antioxidant was not effective evenly to all of antioxidant test.

• Journal of the Microelectronics and Packaging Society
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• v.8 no.3
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• pp.37-42
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• 2001

The concerns of the toxicity and health hazard of lead in solders have demanded the research to find suitable lead-free solder alloys. It was discussed that effect of the intermetallic formation and structure on the reliability of solder joints. In this study, lead-free solder alloys with compositions of Sn/3.5Ag/0.75Cu, Sn/2.0Ag/0.5Cu/2.0Bi were applied to the 48 $\mu$BGA packages. Also, the lead-free solder alloys compared with eutectic Sn/37Pb solder using shear test under various aging temperature. Common $\mu$BGA with solder components was aged at $130^{\circ}C$, $150^{\circ}C$ and $170^{\circ}C$. And the each temperature applied to 300, 600 and 900 hours. The thickness of the intermetallics was measured for each condition and the activation energy for their growth was computed. The fracture surfaces were analyzed using SEM (Scanning Electron Microscope) with EDS (Energy Dispersive Spectroscopy). These results for reliability of lead-free interconnections are discussed.

• Korean journal of applied entomology
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• v.39 no.1
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• pp.53-58
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• 2000

The effect of NeemAzal-T/S was tested by leaf disk method on fecundity, egg mortality, and preference of twospotted spider mite, Tetranychus urticae and its predator mite, Amblyseius womersleyi in the laboratory. Mortalities of T. urticae and A. womersleyi adults were 97.7% and 20.0%, in 100ppm treatment at 72 h after application, respectively. The mean number of eggs laid per T. urticae female adult were 0.0 and 18.5, and those of A. womersleyi were 1.6 and 2.9 at 100 ppm and 0 ppm concentrations, respectively. Hatchability of T. urticae eggs treated with 50 and 100 ppm were 52.8%, and 2.5%, respectively, and those of A. womersleyi eggs were 100% and 91.3%, respectively. Choice and no-choice tests revealed that T. urticae female preferred to alight and oviposit on untreated bean leaf disk with 13.8 to 18.2 eggs per female. In contrast, A. womersleyi female preferred on treated or untreated bean leaf equally. There was no significant differences in the number of consumption of T. urticae eggs by A. womersleyi on treated and untreated bean leaves, except 200 ppm. These results indicate that NeemAzal-TIS is highly toxic to T. urticae, and is less toxic to A. womersleyi. It may be concluded with these results that NeemAzal-T/S could be incorporated into integrated T. urticae management system.

• Journal of the Korea Concrete Institute
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• v.23 no.3
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• pp.311-320
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• 2011

Fly ash (FA), byproduct from power plant has been actively used as mineral admixture for concrete. However, since bottom ash (BA) is usually used for land reclaim or subbase material, more active reuse plan is needed. Pond ash (PA) obtained from reclaimed land is mixed with both FA and BA. In this study, 6 PA from different domestic power plant are prepared and 5 different replacement ratios (10%, 20%, 30%, 50%, and 70%) for fine aggregate substitutes are considered to evaluate engineering properties of PA as fine aggregate and durability performance of PA concrete. Tests for fine aggregate of PA for fineness modulus, density and absorption, soundness, chloride and toxicity content, and alkali aggregate reaction are performed. For PA concrete, durability tests for compressive strength, drying shrinkage, chloride penetration/diffusion, accelerated carbonation, and freezing/thawing are performed. Also, basic tests for fresh concrete like slump and air content are performed. Although PA has lower density and higher absorption, its potential as a replacement material for fine aggregate is promising. PA concrete shows a reasonable durability performance with higher strength with higher replacement ratio. Finally, best PA among 6 samples is selected through quantitative classification, and limitation of PA concrete application is understood based on the test results. Various tests for engineering properties of PA and PA concrete are discussed in this paper to evaluate its application to concrete structure.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.769-772
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• 2008

The problem of disposing construction waste materials has become a national and social problem. Recycled powder generated in the process of making aggregate, and the recycled powder is land-filled in its entirety. Results of toxicity testing of recycled power show that it contains base-pair substituent mutagenicity. As recycled powder is disposed of as landfill, it can cause secondary contamination such as soil and underground water contamination. There has been very little research made on recycled powder. This study has examined the utilization of concrete mixture by using recycled powder in a mixture instead of cement and compared and analyzed the characteristics of dynamics and workability. This study has examined the application of recycled powder in concrete. Depending on the replacement rate and workability, test piece was manufactured using different mixing rate by CP, WCP, PCP. The CP was used to examine the physical property of concrete and characteristics its dynamics. The letters W of WCP and P of PCP are the initials of water and mixture. They were made using the standard mixing ratiosemphasizing the workability to determine the characteristic of dynamics of concrete based on the mixing ratio of recycled powder. With the increase in the replacement rate, CP had very little change in the strength. But with the decline of slump, the workability was not good. The result of manufacturing WCP and PCP using the standard mixing ratio showed that WCP had a drop in strength compared to the plain. PCP had almost the same value as the plain only when the replacement rate was 10%. When it was higher than that, a reduction in strength was observed.

• Korean Chemical Engineering Research
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• v.50 no.2
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• pp.217-222
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• 2012

The synthesis of dimethyl carbonate(DMC) is a promising reaction for the use of naturally abundant carbon dioxide. DMC has gained considerable interest owing to its versatile chemical reactivity and unique properties such as high oxygen content, low toxicity, and excellent biodegradability. In this study, the synthesis of DMC through the transesterification of ethylene carbonate(EC) with methanol was investigated by using ionic liquid and metal oxide catalysts. The screening test of different catalysts revealed that choline hydroxide ([Choline][OH]) and 1-n-butyl-3-methyl imidazolium hydroxide([BMIm][OH]) had better catalytic performance than metal salts catalysts such as MgO, ZnO and CaO. The effects of reaction parameters such as reaction temperature, MeOH/EC mole ratio, and carbon dioxide pressure on the reactivity of [Choline][OH] catalyst were discussed. High temperature and high MeOH/EC mole ratio were favorable for high conversion of EC. However, the yield of DMC showed a maximum when carbon dioxide pressure was 1.34 MPa, and then it decreased for higher carbon dioxide pressure. Zinc chloride($ZnCl_2$) was used as co-catalyst with the ionic liquid catalyst. The mixed catalyst showed a synergy effect on the EC conversion and DMC yield probably due to the acid-base properties of the catalysts.

• KSBB Journal
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• v.30 no.4
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• pp.148-154
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• 2015

Onion (Allium cepa) is one of the flavonoids-rich materials in human diet and onion peel, which is the onion by-products, contains over 20 times more quercetin than the flesh. In this study, to examine the anti-inflammatory effects of onion peel hot water extract (OPHWE), the cell viability, nitric oxide (NO), pro-inflammatory cytokines, such as interluekin-6 (IL-6), tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$), and IL-$1{\beta}$, were measured using the murine macrophage cell line RAW 264.7 cells. The Balb/c mice were used for an in vivo acute toxicity test and ICR mice were used for measurement of inhibition effects of croton oil-induced mouse ear edema. As a result, NO levels decreased in a dose-dependent manner. The production of IL-6, TNF-${\alpha}$, and IL-$1{\beta}$ was suppressed by 38%, 41%, and 34% respectively, compared with that of the LPS only group, without any cytotoxicity. The edema formation in the ICR mouse ear was also reduced compared to that in control. Moreover, there were no mortalities occurred in mice administered 5,000 mg/kg body weight of OPHWE. These results suggest that OPHWE has considerable anti-inflammatory activities and can be regarded as a potent candidate material to treat inflammatory diseases.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.2 s.51
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• pp.147-152
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• 2005

As a part of searching tot the natural components which inhibit the skin aging and wrinkle formation, the $80\%$ methanolie extracts of 121 species of traditional herbal medicines used to treat lung and skin disease were investigated for their in vitro anti-oxidative activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide radicals, and inhibitory activity against elastase. We selected 9 kinds of the traditional herbal medicines showing inhibitory activities of winkle formation. The effective concentrations of 9 candidates for anti-wrinke/skin firming activity was less than 0.1 mg/mL, and there is no toxicity to cell viability at these concentrations. Through analysis of human skin primary patch test data, the traditional herbal medicines represented non-irritant materials. We suggest that these 9 candidates with ability to help anti-wrinkle/skin firming may be useful for functional cosmetic materials.