• 제목/요약/키워드: Isolation Resistance

검색결과 405건 처리시간 0.028초

마찰진자형 면진베어링의 특성 연구 (A study on the characteristics of friction pendulum isolation bearings)

  • 김영중
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2000년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2000
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    • pp.407-414
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    • 2000
  • The friction pendulum type seismic isolation system (FPS) has been developed to provide a simple and effective way to achieve earthquake resistance for buildings . The major advantages are: the isolation frequency can be easily achieved by designing a curvature of the surface and does not depend on the supported weight of a structure. The function of carrying vertical load is separated to the function of providing horizontal stiffness. Next the friction provides sufficient energy dissipation to protect the structure from earthquake response and resistance to the weak external disturbances such as wind load and ground vibrations due to traffic. In this paper, the friction coefficients are evaluated from number of experiments on the FPS test specimens. The relations between friction coefficient and the test waveform, velocity, and pressure are reviewed and further works are discussed.

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깔짚 교체 및 재사용 육계농장 분리 대장균의 항생제 내성 양상 (Patterns of antibiotic resistance in Escherichia coli isolated from fresh and recycled poultry litter)

  • 성환우;최강석;권혁무;이영주
    • 대한수의학회지
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    • 제57권3호
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    • pp.189-195
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    • 2017
  • The isolation rate of Escherichia (E.) coli in poultry litter was investigated at 44 broiler farms, 20 that used fresh litter and 24 that used recycled litter. The patterns of resistance to antibiotics of the E. coli isolates were compared. In litter sampled before the rearing period, the isolation rate of E. coli was higher at farms that used fresh litter; E. coli was present in the litter in 94.5% (35 out of 37 flocks tested) of the farms that used fresh litter vs. 51.2% (21 out of 41 flocks) of the farms that used recycled litter. The susceptibility of the 93 isolates of E. coli to 13 antibiotics was studied. Before the rearing period, E. coli isolates from the farms that recycled litter showed higher resistance rates than isolates from farms that replaced litter with fresh litter. Comparing the antibiotic resistance patterns of isolates from litter sampled before and at the end of the rearing period, the antibiotic resistance rates at the end of the rearing period increased dramatically compared with rates before the rearing period.

인천지역 해양환경에서 분리된 비브리오패혈증군의 분포 및 항생제 내성 양성 (Distribution and Antibiotic Resistance of Vibrio vulnificus isolated in Incheon Coastal Area)

  • 황경화;오보영;공용우;이제만;고종명;김용희
    • 환경위생공학
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    • 제22권4호
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    • pp.55-63
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    • 2007
  • We investigated the distribution and drug susceptibility test of V. vulnificus isolated from environmental sources in Incheon. In this survey, total 4,302 samples were obtained from different sites of the Incheon coastal area during the periods from march 2004 to November 2006. Among the 4,302 samples, 310 strains were isolated. The isolation rates of Vibrio vulnificus from fish, shellfish, estuarine water and sediment were 6.7%, 4.7%, 12.4% and 23.2%, respectively. The highest isolation rate was 14.6% in September and in spite of low temperature the isolation rate was 5.1% in November. The highest rate of antibiotic resistance was observed against streptomycin(15.3%), cefazolin(8.5%), cephalothin(8.3%), amikacin(8.3%), cefoxitin(6.7%) and nalidixic acid(6.7%). Seventeen percent of isolates were observed to be resistant to two or more of the antibiotics tested.

수소연료전지자동차의 절연성능 평가방법에 관한 고찰 (Study on the Evaluation Method of Electrical Isolation Property for Hydrogen Fuel Cell Vehicle)

  • 이기연;김동욱;김향곤
    • 한국수소및신에너지학회논문집
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    • 제22권6호
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    • pp.810-818
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    • 2011
  • This paper analyzed the suitability about the isolation performance criteria which was based on human impedance and effect of current in IEC 60479-1 on the safety of human being was examined. The method of evaluation by megger and DC voltmeter was analyzed. The differences of isolation performance according to design of high-voltage system were analyzed. The factors which affect the insulation performance were analyzed for HFCV, EV, HEV, etc. through analysis of the isolation performance evaluation method. Finally, design for improved isolation performance was proposed.

펨토초 레이저를 이용한 은 나노 와이어 필름 전기적 절연 (Electrical Isolation of Ag Nanowire Film using Femtosecond Laser)

  • 윤지욱;박정규;다니엘뵈머;세바스찬잰더;조성학
    • 한국정밀공학회지
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    • 제29권3호
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    • pp.334-338
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    • 2012
  • Electrical isolation of Ag nanowire, which is one of the candidates as electrode for display devices, on polymer with femtosecond pulse laser has been investigated. Line patterning to Ag nanowire with various pulse energy and scan speed were experimented. Duo to the results of the line patterning experiment, we fabricated the isolated squares and measured electrical resistance. The profile of the selectively ablated area was analyzed with AFM(Atomic Force Microscope). The width of the patterned line was $1.8\;{\mu}m$ and the depth was $1.6\;{\mu}m$. We demonstrated electrical isolation of the Ag nanowire using femtosecond laser by evaluating the electrical resistance of the sample between isolated and opened area.

Isolation of a Multidrug Resistance Inhibitor from Aconitum pseudo-laeve var. erectum

  • Kim, Dae-Keun;Kwon, Hyog-Young;Lee, Kang-Ro;Rhee, Dong-Kwon;Zee, Ok-Pyo
    • Archives of Pharmacal Research
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    • 제21권3호
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    • pp.344-347
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    • 1998
  • To overcome multidrug resistance (MDR) in cancer chemotherapy, we prepared various plant extracts and searched for a component which is effective for inhibition of MDR. MDR inhibition activity was determined by measuring cytotoxicity to MDR cells using multidrug resistant human fibrocarcinoma KB V20C, which is resistant to 20 nM vincristine and expresses high level of mdr1 gene. Of various plant extracts, the MeOH extract of the root of Aconitum pseudo-laeve var. erectum was found to have potent inhibitory activity on MDR. The bioassayguided fractionation of the MeOH extract of the plant led to the isolation of an alkaloid, lycaconitine, as an active principle. And the $IC_{50}$ of lycaconitne for KB V20C cells was $74\mu{g}$/ml.

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Partial-isolation LDMOS의 항복전압과 온저항 분석 (Breakdown Voltage and On-resistance Analysis of Partial-isolation LDMOS)

  • 김신욱;이명진
    • 전기전자학회논문지
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    • 제27권4호
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    • pp.567-572
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    • 2023
  • 본 논문에서는 Partial isolation lateral double diffused metal oxide semiconductor(Pi-LDMOS)의 항복전압에 대해 시뮬레이션을 통해 분석하였다. 항복전압 변화는 Partial buried oxide(P-BOX)의 다양한 파라미터(길이, 두께, 위치)에 따라 조사되었고, 그 메커니즘에 대해 명기하였다. 또한 항복전압과 trade-off 관계에 있는 온저항의 변화를 P-BOX 파라미터 변화에 따라 분석하였고 Figure of merit(FOM)을 계산하여 비교하였다. 제안된 구조에서 Lbox=5㎛, tbox=2㎛, Lbc=2㎛일 경우 138V의 가장 높은 항복전압을 나타내었고, Lbox=5㎛, tbox=1.6㎛, Lbc=2㎛일 경우 가장 높은 FOM을 나타내었다. 이는 conventional LDMOS 대비 항복전압은 123%, FOM은 3.89배 향상된 수치이다. 따라서 Pi-LDMOS는 높은 항복전압과 FOM을 가져 Power IC의 안정적인 동작범위 향상에 기여할 수 있다.

동축-원추-방사형 전력분할/합성기의 중심부 높이에 따른 최적설계와 아이솔레이션 특성 향상 (On the Optimization of the Coaxial-Conical-Radial Type Power Divider/Combiner and the Improvement of Isolation Characteristics)

  • 최영규
    • 전기학회논문지
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    • 제60권9호
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    • pp.1727-1732
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    • 2011
  • In order to realize a high performance(low loss, high isolation) microwave power divider/combiner, we have designed the power combiner/divider precisely in accordance with the different hight of central part. In the case of the high central part of the hight of $h_r$=10.2, a compensating part of the conical line is inserted in the conical conversion transmission line, and in the case of low central part of the hight of $h_r$=5.0, the conical conversion transmission line is remodeled into the 2-stage bend structure. In both case, the reflection characteristics are improved to 30dB over the operating frequency range of 5GHz bandwidth. A resistance is inserted between the peripheral ports so as to try to improve the isolation characteristics of the device. For the 16-divider/combiner, the isolation characteristics are improved to 10dB over the operating frequency range of 5GHz bandwidth.

Bacterial determinants involved in the induction of systemic resistance ana plant growth promotion in tobacco by Pseudomonas chlororaphis O6.

  • Han, Song-Hee;Cho, Baik-Ho;Kim, Young-Cheol
    • 한국식물병리학회:학술대회논문집
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    • 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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    • pp.101.2-102
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    • 2003
  • The ability of P. chlororaphis O6 to induce resistance to Erwinia carotovora subsp. carotovara SCCI and to promote growth in tobacco was demonstrated in microtiter assays on plants pre-inoculated at the root level with the bacteria before challenge with the leaf pathogen. To identify th bacterial determinants involved in induced systemic resistance and plant growth promotion, cell culture of O6 grown in King's medium B was fractionated with organic solvents and purified using various columns. in vivo and in vitro assays with samples from successive fractionation steps of the O6 supernatant led to the conclusion that antibacterial compounds were observed in aqueous layer, and to the isolation of fractions containing metabolites that retained most of the resistance-inducing activity (70:30, methanol:water) and the plant growth promotion (80:20 and 90:10, methanol:water) after ODS column chromatography. Although these molecules remain to be purified further and structurally characterized, its isolation is an addition to the range of determinants from plant growth-promoting rhizobacteria known to stimulate plant defence.

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