• Journal of the Korean Society of Food Culture
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• v.20 no.5
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• pp.603-607
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• 2005

Fourteen phenolic compounds(benzoic acid, p-hydroxybenzoic acid, protocatechuic acid, vanillic acid, syringic acid, gallic acid, caffeic acid, ferulic acid, (+)-catechin, quercetin, rutin, catechol, chlorogenic acid and L-ascorbic acid) were examined for their effects on the anticarigenic activity. Among tested samples, catechol was significantly inhibited the S. mutans, exhibiting an clear zone 18.5-19.5mm by 10 mg/disc level. The minimal inhibition concentration(MIC) of the phenolic compounds for Streptococcus mutans, M1 and M2 strain were determined as 2,000 ppm, whereas catechol was 1,000 ppm. The activity of glucosyltransferase(GTase) was significantly inhibited by catechol, at 10 ppm(58.7%), 50 ppm(60.7%) and 100 ppm(88.4%) and 500 ppm(89.6%), respectively. Among them, catechol showed most significant anticariogenic activity as well as inhibition of GTase activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1214-1220
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• 2003

Antimicrobial activity of Rhus javanica (RJ) extract against animal husbandry disease-related bacteria was determined by a paper disc method. The RJ extracts showed a significant antimicrobial activity against Gram positive (+) bacteria and especially the activity was most potent against L. monocytogenes and S. epidermidis. Minimum inhibitory concentrations (MIC) of the MeOH and EtOH extracts of RJ were in the range of 0.8 ∼ 16 mg/mL and 0.8 ∼ 10 mg/mL, respectively. Furthermore, among five solvent fractions (n-hexane, CHC1$_3$, EtOAc, n-BuOH and $H_2O$ frs.) from MeOH extract of RJ, the EtOAc fr. exhibited the most significant antimicrobial activity The antimicrobial activities of RJ extracts against most microbial strains were unstable by either heat treatment or acid treatment. The inhibitory effect of RJ extracts on microbial cell growth was further examined by the addition of 0, 100, 300, and 500 ppm of RJ extracts into growth medium. The growth of gram positive (+) bacteria, S. aureus, S. epidermidis and L. monocytogenes was inhibited for 72 hours when at least 300 ppm of RJ extracts added, but the growth of gram negative (-) bacteria was only inhibited when at least 500 ppm of RJ extracts were added. Taken together, tile antimicrobial activities of RJ extracts were more effective against gram positive (+) bacteria compared to those against gram negative (-) bacteria.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.2
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• pp.91-97
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• 2014

With Pb-free solder joints containing Sn-Ag-Cu-based ternary alloys (Sn-1.0 wt.%Ag-0.5Cu and Sn-4.0Ag-0.5Cu) and Sn-Ag-Cu-In-based quaternary alloys (Sn-1.0Ag-0.5Cu-1.0In, Sn-1.2Ag-0.5Cu-0.4In, Sn-1.2Ag-0.5Cu-0.6In, and Sn-1.2Ag-0.7Cu-0.4In), fracture-mode change, shear strengths, and fracture energies were observed and measured under a high-speed shear test of 500 mm/s. The samples in each composition were prepared with as-reflowed ones or solid-aged ones at $125^{\circ}C$ to 500 h. As a result, it was observed that ductile or quasi-ductile fracture modes occurs in the most of Sn-Ag-Cu-In samples. The happening frequency of a quasi-ductile fracture mode showed that the Sn-Ag-Cu-In joints possessed ductile fracture properties more than that of Sn-3.0Ag-0.5Cu in the high-speed shear condition. Moreover, the Sn-Ag-Cu-In joints presented averagely fracture energies similar to those of Sn-Ag-Cu joints. While maximum values in the fracture energies were measured after the solid aging for 100 h, clear decreases in the fracture energies were observed after the solid aging for 500 h. This result indicated that reliability degradation of the Sn-Ag-Cu-In solder joints might accelerate from about that time.

• Korean Journal of Plant Resources
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• v.27 no.5
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• pp.421-428
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• 2014

In general, Reucedani Radix (Peucedanum japonicum Thunbergis: PJ) is the Korean traditional herbal medicine used to remove dampness, to relieve pain, and spasm. So, PJ folium is believed to have the same effects. The aim of this study is to investigate the alleviation of dextran sulfate sodium (DSS) induced ulcerative colitis in mice by PJ folium. 25 mice were divided into 5 groups: normal, DSS, DSS + 100 mg/kg PJ folium (PJ100), DSS + 500 mg/kg PJ folium (PJ500), and DSS + 150 mg/kg 5-amino salicylic acid (5-ASA) groups. Body weights, colon lengths, histological changes in colon tissue, and spleen weights were observed. Inflammatory cytokines such as IL-$1{\beta}$, IL-6, and TNF-${\alpha}$ level in plasma were measured by ELISA. IL-$1{\beta}$, IL-6, and TNF-a mRNA expression in colon tissue were detected by RT-PCR. In the results, body weight lose was inhibited in PJ100, PJ500, and 5-ASA groups, but it was not different compared with DSS group, significantly. PJ500 group showed the preventive effects of colon length shorten and histological changes in colon tissues as good as 5-ASA group. The weight of spleen was increased in DSS group but it reduced in PJ100, PJ500, and 5-ASA groups. Moreover, IL-$1{\beta}$ and TNF-${\alpha}$ cytokine levels in plasma were reduced in PJ500 and 5-ASA groups. IL-$1{\beta}$, IL-6, and TNF-a mRNA expression in colon tissue were inhibited in PJ100, PJ500, and 5-ASA groups and it was significantly different compared with DSS group. In conclusion, PJ folium showed the alleviative effect on DSS induced ulcerative colitis in mice.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.5 s.347
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• pp.1-10
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• 2006

In this paper, an 1.8V 8-bit 500MSPS CMOS A/D Converter is proposed. In order to obtain the resolution of 8bits and high-speed operation, a Cascaded-Folding Cascaded-Interpolation type architecture is chosen. For the purpose of improving SNR, Cascaded-folding Cascaded-interpolation technique, distributed track and hold are included [1]. A novel folding circuit, a novel Digital Encoder, a circuit to reduce the Reference Fluctuation are proposed. The chip has been fabricated with a $0.18{\mu}m$ 1-poly 5-metal n-well CMOS technology. The effective chip area is $1050{\mu}m{\times}820{\mu}m$ and it dissipates about 146mW at 1.8V power supply. The INL and DNL are within ${\pm}1LSB$, respectively. The SNDR is about 43.72dB at 500MHz sampling frequency.

• Korean Journal of Food Science and Technology
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• v.41 no.6
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• pp.694-699
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• 2009

The antimutagenic activities of ethanol extracts of Korean and American propolis were tested using Salmonella Typhimurium TA98 with two indirect mutagens of 3-amino-1,4-dimethyl-5H-pyrido [4,3-b]indole (Trp-P-1) and 2-aminoanthracene (2-AA) with S9 mix. Additionally, their antimicrobial activities against acne-related pathogenic strains of Propionibacterium acnes, Staphylococcus Epidermidis, Staphylococcus aureus and Pseudomonas aeruginosa were evaluated using both paper disk method and agar dilution method. Ethanol extracts of Korean and American propolis showed strong inhibitory effects, in a dose dependant manner, against the mutagenicities induced by Trp-P-1 and 2-AA. The antimutagenic effect of ethanol extracts of Korean propolis showed significantly higher protective activity than that of American propolis against the Trp-P-1 induced mutagenicity of S. Typhimurium TA98 at the lower concentration ($1-10\;{\mu}g$), but significantly lower protective activity at the higher concentration ($50-200\;{\mu}g$). The antimutagenic effect of ethanol extract of Korean propolis showed significantly higher protective activity than that of American propolis against the 2-AA induced mutagenicity at the concentration of $1\;{\mu}g$, but significantly lower protective activity than that of the American at the higher concentration ($50-200\;{\mu}g$). Both extracts showed strong antimicrobial activities against all the acne-related pathogens tested, with minimal inhibitory concentration (MIC) values in the range $1,500-5,000\;{\mu}g/mL$.

• Korean Journal of Microbiology
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• v.37 no.3
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• pp.189-196
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• 2001

Eighty-seven microbial strains capable of growing on bisphenol A (BPA) as a sole carbon source were isolated from soils, waste waters and sludges. Among them, three bacterial strains were finally selected as potential decomposers through measuring BPA-degradation efficiency by HPLC analysis. Two of these bacterial strains were identified as Serratia marcescens 1901 and S. marcescens 1902, and another was Pseudomonas putida 1401 by 16S rDNA partial sequences and based on morphological and physiological properties. They showed higher cell growth and BPA degradation in PAV (PAS medium containing vitamin mixtures) than in PAS medium. The degradation efficiencies of these bacterial strains were within a range of 20-40% in the PAV containing 500 mg/1 or 100 mg/l of BPA fur 3 days. S. marcescens 1901 showed higher degradation efficiency at 100 mg/1 of BPA than those of other selected strains, while S. marcescens 1902 and P. putida 1401 degraded a high concentration of BPA (500 mg/l) with a degradation efficiency of 40% for 3 days. The BPA degradation using a mixed culture of three selected strains showed the similar level of dog-radation efficiency with that using a pure culture.

• Journal of The Geomorphological Association of Korea
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• v.19 no.2
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• pp.173-185
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• 2012

Authors performed pollen analysis in deposits at a coastal plain at Yeongjong-do Island located in Incheon, South Korea. Sampling site (7.2 m a.s.l.) belongs to the cool temperate deciduous broad-leaf forest. Environmental changes since 8,900 yrs B.P. reconstructed from pollen analysis are as follows; JS-I stage (c.a. 8,900~8,500 yrs B.P. ) was cool temperate northern mixed-forest which is comparable to the early PostGlacial pollen stage RI in Japan, in which Pinus and Quercus were dominant and Abies and Picea were also found. At that time, climate was relatively cooler and dryer than today. JS-II stage (sometime between 8,500~4,000 yrs B.P.) was Pinus-dominant coniferous forest, which is comparable to the mid-Post-Glacial pollen stage RII. Mixed forest of Pinus, Quercus and Carpinus was dominant in JS-III stage (c.a. 4,000 yrs B.P). We assumed that JS-II and JS-III stage were relatively warmer and more humid than JS-I stage, and were more like present conditions. JS-IV stage (sometime between 4,000~900 yrs B.P.) was Pinus-dominant coniferous forest which is comparable to the late Post-Glacial pollen stage RIII. JS-V stage (c.a. 900 yrs B.P. ~present) was second growth Pinus-dominant coniferous forest stage. During the last stage, non-arboreal pollen was more common than arboreal pollen and Fagopyrum appeared among the herbaceous plant, which indicates that it is comparable to the RIIIb stage which was the age of human interference. From the JS-V stage, humans in the study site started agricultural activities.

• Transactions of the Korean hydrogen and new energy society
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• v.13 no.4
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• pp.259-269
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• 2002

A battery based on the lithium/elemental sulfur redox couple has the advantage of high theoretical specific capacity of 1,675 mAh/g-sulfur. However, Li/S battery has bad cyclic durability at room temperature due to sulfur active material loss resulting from lithium polysulfide dissolution. To improve the cycle life of Li/S battery, PEGDME (Poly(ethylene glycol) dimethyl ether) 500 containing 1M LiTFSI salt which has high viscosity was used as electrolyte to retard the polysulfide dissolution and nano-sized $Mg_{0.6}Ni_{0.4}O$ was added to sulfur cathode as additive to adsorb soluble polysulfide within sulfur cathode. From experimental results, the improvement of the capacity and cycle life of Li/S battery was observed( maximum discharge capacity : 1,185 mAh/g-sulfur, C50/C1 = 85 % ). Through the charge-discharge test, we knew that PEGDME 500 played a role of preventing incomplete charge-discharge $behavior^{1,2)$. And then, in sulfur dissolution analysis and rate capability test, we first confirmed that nano-sized $Mg_{0.6}Ni_{0.4}O$ had polysulfide adsorbing effect and catalytic effect of promoting the Li/S redox reaction. In addition, from BET surface area analysis, we also verified that it played the part of increasing the porosity of sulfur cathode.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.329-333
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• 1997

Rheological properties of partially purified fucoidans of Laminaria religiosa, sporophylls of Undaria pinnatifida, Hizikia fusiforme, and Sargassum fulvellum in Korea were investigated, The fucoidans produced aqueous solutions of low apparent viscosity with pseudoplastic flow behavior. The viscosity of $5\%$ solution of the fucoidan from sporophylls of U. pinnatifida was 2.2 mPa.s. The activaton energies of L. religiosa, sporophylls of U. pinnatifida, H. fusiforme and S. fulvellum were $8.269\times10^6,\;7.498\times10^6,\;7.141\times10^6,\;and\;6.677\times10^6\;J/Kg.mol$ at 1,500 1/s of shear rate, respectively. The viscosity of the fucoidan solution was increased by the addition of sugar, but that was not changed by addition of NaCl.