• Title, Summary, Keyword: $B_{18}$

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Bacillus spp. & B. cereus Isolated in Dried Marine Products (시판 건포류에서 B. cereus 관련 균주 분리와 항생제 감수성)

  • Ham Hee-Jin;Kim Moo-Sang
    • Journal of Food Hygiene and Safety
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    • v.21 no.3
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    • pp.159-163
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    • 2006
  • 37 Bacillus spp strains(43.0%=37/86), and 18 B. cereus(20.9%=18/86) were isolated on 86 dried marine products. Each isolates were B. cereus 48.6%(18/37), B. mycoides 13.5%(5/37) B. coagulus 5.4%(2/37) B. firmus 5.4%(2/37), B. circulus 2.7%(1/37), B. stearothermophilus 2.7%(1/37), B. pumilus 2.7%(1/37) B. spp. 8.1%(3/37), and Brebacillus brevis 10.8%(4/37) etc.

Effects of Phytophthora Blight-antagonistic Microorganisms Bacillus subtilis AH18 and Bacillus licheniformis K11 on the Soil Microbial Community (고추역병 길항미생물 Bacillus subtilis AH18과 Bacillus licheniformis K11의 토양미생물 생태에 미치는 영향)

  • Park, Kee-Choon;Lim, Jong-Hui;Kim, Sang-Dal;Yi, Young-Keun
    • Journal of Applied Biological Chemistry
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    • v.52 no.3
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    • pp.121-125
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    • 2009
  • We measured the influence of antifungal antagonists Bacillus subtilis AH18 and Bacillus licheniformis K11 on soil microbial community in microcosms. Both antifungal antagonists were confirmed to suppress hot pepper phytophthora blight. Phospholipid fatty acids (PLFA) were analyzed to investigate the soil microbial community. B. subtilis AH18 changed the total PLFA composition and bio-indicators of PLFA, compared with other treatments. B. subtilis AH18 decreased the proportion of bacteria and gram negative/gram positive bacteria, and increased the fungi/bacteria and anaerobic/aerobic microorganisms. In addition cy19:0/18:$1{\omega}7c$, which means adaptation to unfavorable environmental conditions, was increased by the application of B. subtilis AH18. On the other hand the inoculation of B. licheniformis K11 or combined inoculation of both antifungal strains did not affect soil microbial community. The suppression of phytophthora blight and preservation of indigenous soil microbial community may be achieved by the combined application of B. subtilis AH18 and B. licheniformis K11.

6-18 GHz MMIC Drive and Power Amplifiers

  • Kim, Hong-Teuk;Jeon, Moon-Suk;Chung, Ki-Woong;Youngwoo Kwon
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.2 no.2
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    • pp.125-131
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    • 2002
  • This paper presents MMIC drive and power amplifiers covering 6-18 ㎓. For simple wideband impedance matching and less sensitivity to fabrication variation, modified distributed topologies are employed in the both amplifiers. Cascade amplifiers with a self-biasing circuit through feedback resistors are used as unit gain blocks in the drive amplifier, resulting in high gain, high stability, and compact chip size. Self impedance matching and high-pass, low-pass impedance matching networks are used in the power amplifier. In measured results, the drive amplifier showed good return losses ($S_11,{\;}S_{22}{\;}<{\;}-10.5{\;}dB$), gain flatness ($S_{21}={\;}16{\;}{\pm}0.6{\;}dB$), and $P_{1dB}{\;}>{\;}22{\;}dBm$ over 6-18 GHz. The power amplifier showed $P_{1dB}{\;}>{\;}28.8{\;}dBm$ and $P_{sat}{\;}{\approx}{\;}30.0{\;}dBm$ with good small signal characteristics ($S_{11}<-10{\;}dB,{\;}S_{22}{\;}<{\;}-6{\;}dB,{\;}and{\;}S_{21}={\;}18.5{\;}{\pm}{\;}1.25{\;}dB$) over 6-18 GHz.

Synthesis and Photodynamic Activities of Pyrazolyl and Cyclopropyl Derivatives of Purpurin-18 Methyl Ester and Purpurin-18-N-butylimide

  • Yoon, Il;Park, Ho-Sung;Cui, Bing Cun;Kim, Jung-Hwa;Shim, Young-Key
    • Bulletin of the Korean Chemical Society
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    • v.32 no.1
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    • pp.169-174
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    • 2011
  • The synthesis of new pyrazolyl and cyclopropyl derivatives of purpurin-18 methyl ester and purpurin-18-N-butylimide 1a, 1b, 2a, 2b and 8 is described. The new compounds were characterized by NMR, UV-vis spectroscopy and mass spectrometry. UV-vis spectra of the new compounds showed long wavelength absorption of ranges 692 - 708 nm ($\lambda_{max}$). Photodynamic effects of the chlorin derivatives 1a, 1b, 2a and 2b were investigated by WST-1 assay in A549 cells, and showed good photodynamic activities with high photocytotoxicity and low cytotoxicity in the dark. In comparison between pyrazolyl and cyclopropyl derivatives, purpurin-18 methyl ester compounds 1a and 1b showed comparable photocytotoxicity result of the cell viabilities, otherwise, pyrazolyl derivative of purpurin-18-N-butylimide 2a showed better cell viabilities than those of cyclopropyl derivative 2b. And cyclopropyl derivative of purpurin-18-N-butylimide 2b showed higher dark cytotoxicity than that of others.

Inductor-less 6~18 GHz 7-Bit 28 dB Variable Attenuator Using 0.18 μm CMOS Technology (0.18 μm CMOS 기반 인덕터를 사용하지 않는 6~18 GHz 7-Bit 28 dB 가변 신호 감쇠기)

  • Na, Yun-Sik;Lee, Sanghoon;Kim, Jaeduk;Lee, Wangyoung;Lee, Changhoon;Lee, Sungho;Seo, Munkyo;Lee, Sung Chul
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.27 no.1
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    • pp.60-68
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    • 2016
  • This paper presents a 6~18 GHz 7-bit digital-controlled attenuator. The proposed attenuator is based on switched-T architecture, but no inductor is used for minimum chip size. The designed attenuator was fabricated using $0.18{\mu}m$ CMOS process, and characterized using on-wafer testing setup. The resolution(minimum attenuation step) and the maximum attenuation range of the attenuator were measured to be 0.22 dB and 28 dB, respectively. The measured RMS attenuation error and the RMS phase error for 6~18 GHz were less than 0.26 dB and $3.2^{\circ}$, respectively. The reference state insertion loss was less than 12.4 dB at 6~18 GHz. The measured input and output return losses were better than 9.4 dB over all frequencies and attenuation states. The chip size is $0.11mm^2$ excluding pads.

EVALUATION ON THE ABRASION RESISTANCE OF A SURFACE SEALANT (레진전색제의 마모저항성에 대한 평가)

  • Kim, Soo-Mee;Han, Sae-Hee;Cho, Young-Gon
    • Restorative Dentistry and Endodontics
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    • v.32 no.3
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    • pp.180-190
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    • 2007
  • The purpose of this study was to evaluate the abrasion resistance of surface penetrating sealant which was applied on a composite resin restoration and to provide proper time to reapply sealant on composite resin surface. Two hundred rectangular specimens, sized $8\times3\times2mm$, were made of Micronew (Bisco, Inc., Schaumburg, IL, U.S.A) and divided into two groups; F group (n = 10) was finished with coarse and medium grit of Sof-Lex discs and BisCoverwas applied B group (n = 190) after finishing with discs. B group was again subdivided into nineteen subgroups From B-1 group to B-18 group were subjected to toothbrush abrasion test using a distilled water-dentifrice slurry and toothbrush heads B-IM group was not subjected to toothbrush abrasion test. Average surface roughness (Ra) of each group was calculated using a surface roughness tester (Surfcorder MSE-1700: Kosaka Laboratory Ltd., Tokyo, Japan) . A representative specimen of each group was examined by FE-SEM (S-4700: Hitachi High Technologies Co., Tokyo, Japan). The data were analysed using cluster analysis, paired t-test, and repeated measure ANOVA. The results of this study were as follows; 1. Ra off group was $0.898{\pm}0.145{\mu}m$ and B-IM group was $0.289{\pm}0.142{\mu}m$. Ra became higher from B-1 group $(0.299{\pm}0.48{\mu}m$ to B-18 group $(0.642{\pm}0.313{\mu}m$. 2. Final cluster center of Ra was $0.361{\mu}m$ in cluster 1 $(B-IM\simB-7)$, $0.511{\mu}m$ in cluster 2 $(B-8\simB-14)$ and $0.624{\mu}m$ in cluster 3 ($(B-15\simB-18)$. There were significant difference among Ra of three clusters. 3 Ra of B-IM group was decreased 210.72% than Ra of F group. Ra of B-8 group and B-15 group was increased 35.49% and 51.35% respectively than Ra of B-IM group. 4. On FE-SEM, B-IM group showed the smoothest resin surface. B-8 group and B-15 group showed vertically shallow scratches , and wide and irregular vertical scratches on composite resin surface respectively. Within a limitation of this study, finished resin surface will be again smooth and glazy if BisCover would be reapplied within 8 to 14 months after applying to resin surface.

Growth Behavior of Aluminum Borate Whisker under 2.45 GHz Electromagnetic Irradiation (2.45 GHz 전자기파 조사하에서 Aluminum Borate Whisker의 성장 거동)

  • 김성완;이상근;김지경;이창희;안진모;신준식;박성수;박희찬
    • Journal of the Korean Ceramic Society
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    • v.40 no.10
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    • pp.998-1004
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    • 2003
  • With starting materials of two different powder mixtures, $Al_2$(S $O_4$)$_3$+xNa$_2$B$_4$ $O_{7}$$.$10$H_2O$(㏖ ratio; x=0.1, 0.7) and ${\gamma}$-Al$_2$ $O_3$+xNa$_2$B$_4$ $O_{7}$$.$10$H_2O$(㏖ ratio; x=0.1, 0.7), whisker-type $Al_{18}$B$_4$ $O_{33}$ particles were synthesized by using conventional and microwave heat-treatment. The effects of microwave, amount of flux and temperature on the growth of whisker-type $Al_{18}$B$_4$ $O_{33}$ particles were investigated by using X-Ray Diffractometry (XRD) and Scanning Electron Microscopy (SEM). With increase of heat-treatment temperature and amount of flux, the size of whisker-type $Al_{18}$B$_4$ $O_{33}$ particles increased in both conventional and microwave heat-treated samples. However, compared to the conventional heat-treated samples, whisker-type $Al_{18}$B$_4$ $O_{33}$ particles were well grown for the microwave heat-treated samples.ted samples.

Studies on the Free Fatty Acids of Domestic Butter (국산 버터 중의 유리지방산에 관한 연구)

  • Song, Geun-Seoup;Kwon, Yong-Ju;Yang, Hee-Cheon;Lee, Tae-Kyoo
    • Korean Journal of Food Science and Technology
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    • v.22 no.5
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    • pp.526-529
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    • 1990
  • Free fatty acids of two brands of domestic butter were isolated directly by a modified silicic acid column chromatography, and were analyzed by gas liquid chromatography. $C_{18}$ FFA congeners $(C_{18_0},\;C_{18:1},\;C_{18:2}\;and\;C_{18:3})$ were the predominant components (52.83% in brand A and 47.50% in brand B), followed by $C_{16}$FFA (29.39% in brand A and 30.52% in brand B) and $C_{14}$FFA (11.85% in brand A and 13.76% in brand B). The other FFA were present as minor components (0.29-3.87%). Concentrations of four FFA $(C_4,\;C_6,\;C_{10}\;and\;C_{12})$FFA which would be expected to contribute strongly to hydrolytic rancidity off-flavors were below individual threshold level, except $C_4FFA$ (56 ppm) in butter B.

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Microstructure and Corrosion Properties of Plasma Electrolytic Oxide Coatings on AZ31 Magnesium Matrix Composite (플라즈마 전해 산화 처리한 AZ31 및 Al18B4O33w/AZ31 마그네슘 복합재료 피막의 미세구조 및 부식특성)

  • Cheon, Jinho;Park, Yongho;Park, Ikmin
    • Korean Journal of Metals and Materials
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    • v.49 no.3
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    • pp.270-274
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    • 2011
  • Plasma electrolytic oxidation (PEO) treatment was performed on squeeze cast AZ31 alloy and $Al_{18}B_4O_{33}w/AZ31$ composite. Scanning electron microscope (SEM) was employed to characterize the surface morphology and cross-section microstructure of the coating. The phase structures of the PEO coating were analyzed by X-ray diffraction (XRD). The corrosion resistance of the PEO coating was evaluated by electrochemical method. The results showed that the $Al_{18}B_4O_{33}$ whisker on the surface of the composite was decomposed and $MgAl_2O_4$ was formed in the PEO coating layer of $Al_{18}B_4O_{33}w/AZ31$ composite during PEO treatment. As a result, the electrochemical corrosion potential of the PEO coated $Al_{18}B_4O_{33}w/AZ31$ composite was increased compared with that of AZ31 alloy.

A Design on UWB LNA for Using $0.18{\mu}m$ CMOS ($0.18{\mu}m$ CMOS공정을 이용한UWB LNA)

  • Hwang, In-Yong;Jung, Ha-Yong;Park, Chan-Hyeong
    • Proceedings of the IEEK Conference
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    • pp.567-568
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    • 2008
  • In this paper, we proposed the design on LNA for $3{\sim}5\;GHz$ frequency with Using $0.18{\mu}m$CMOS technology. The LNA gain is 12-15 dB, and noise figure is lower than 5 dB and Input/output matching is lower than 10 dB in frequency range from 3 GHz to 5 GHz. The topology, which common source output of cascode is reduced noise figure and improved gain. Input common gate amplifier extend LNA's bandwidth.

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