• 제목/요약/키워드: Isolation method

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전기 구동 차량의 누설 전류 검출 기법 (The Method for detecting leakage current of a electric vehicle)

  • 박현석;엄정용
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2011년도 추계학술대회 초록집
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    • pp.139.1-139.1
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    • 2011
  • Electric vehicle use independent electricity of high voltage. if isolation of electricity is destructed, devices and people are considerably damaged. Therefore, detection of ground fault is necessary for electric vehicle. As the existing detection method of ground fault can not detect ground fault when isolation of both positive side and negative side of electricity is destructed, and change of voltage of electricity. This paper proposed detection method for ground fault of both two sides of electricity and change of voltage. The proposed method is verified by analysis of equivalent circuit.

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3상 4선식 인터링킹 컨버터의 1선 지락 사고 발생 시 3D SVM 기법 (A New 3D SVM Method under Single-Line-to-Ground Fault in Three Phase Four Wire Interlinking Converter)

  • 안창균;최봉연;김미나;강경민;이훈;원충연
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2019년도 추계학술대회
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    • pp.106-107
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    • 2019
  • This paper propose a new 3D SVM method for three-phase four wire inverter for fault isolation at a single line ground fault. The available switching combination for isolation of a single line ground fault was analyzed. Using this method, voltage vector diagrams according to each switching combination were classified according to various ground fault situations, and 3D SVM method was performed by generating command for fault isolation. The proposed methods are mathematically analyzed and verified by PSIM simulation.

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광곽향(Pogostemon cablin Benth.)으로부터 Patchouli alchol의 분리 및 함량분석 (Isolation and Quantitative Determination of Patchouli alcohol from Pogostemon cablin Benth.)

  • 김주선;지형준;원도희;강삼식
    • 생약학회지
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    • 제29권1호
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    • pp.18-21
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    • 1998
  • A method for isolation and quantitative determination of patchouli alcohol from Pogostemonis Herba (Pogostemon cablin) has been developed. Isolation of patchouli alcohol was achieved by column chromatography employing the normal-phase gradient separation system n-hexane-ether on silica gel column. The GC method for quantitative determination of patchouli alcohol provided a method for standardization of the raw drug. It suggested that the average content of patchouli alcohol in Pogostemonis Herba is about 0.26%.

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Improving Pneumovirus Isolation Using a Centrifugation and AZD1480 Combined Method

  • Lee, Hansaem;Woo, Hye-Min;Kim, Kisoon;Park, Sehee;Park, Man-Seong;Kim, Sung Soon;Kim, You-Jin
    • Journal of Microbiology and Biotechnology
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    • 제29권12호
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    • pp.2006-2013
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    • 2019
  • The isolation of respiratory viruses, especially from clinical specimens, often shows poor efficiency with classical cell culture methods. The lack of suitable methods to generate virus particles inhibits the development of diagnostic assays, treatments, and vaccines. We compared three inoculation methods, classical cell culture, the addition of a JAK2 inhibitor AZD1480, and centrifugation-enhanced inoculation (CEI), to replicate human respiratory syncytial virus (HRSV) and human metapneumovirus (HMPV). In addition, a combined method using AZD1480 treatment and CEI was used on throat swabs to verify that this method could increase virus isolation efficiency from human clinical specimens. Both CEI and AZD1480 treatment increased HRSV and HMPV genome replication. Also, the combined method using CEI and AZD1480 treatment enhanced virus proliferation synergistically. The combined method is particularly suited for the isolation of interferon-sensitive or slowly growing viruses from human clinical specimens.

A New Isolation and Evaluation Method for Marine-Derived Yeast spp. with Potential Applications in Industrial Biotechnology

  • Zaky, Abdelrahman Saleh;Greetham, Darren;Louis, Edward J.;Tucker, Greg A.;Du, Chenyu
    • Journal of Microbiology and Biotechnology
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    • 제26권11호
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    • pp.1891-1907
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    • 2016
  • Yeasts that are present in marine environments have evolved to survive hostile environments that are characterized by high exogenous salt content, high concentrations of inhibitory compounds, and low soluble carbon and nitrogen levels. Therefore, yeasts isolated from marine environments could have interesting characteristics for industrial applications. However, the application of marine yeast in research or industry is currently very limited owing to the lack of a suitable isolation method. Current methods for isolation suffer from fungal interference and/or low number of yeast isolates. In this paper, an efficient and non-laborious isolation method has been developed and successfully isolated large numbers of yeasts without bacterial or fungal growth. The new method includes a three-cycle enrichment step followed by an isolation step and a confirmation step. Using this method, 116 marine yeast strains were isolated from 14 marine samples collected in the UK, Egypt, and the USA. These strains were further evaluated for the utilization of fermentable sugars (glucose, xylose, mannitol, and galactose) using a phenotypic microarray assay. Seventeen strains with higher sugar utilization capacity than the reference terrestrial yeast Saccharomyces cerevisiae NCYC 2592 were selected for identification by sequencing of the ITS and D1/D2 domains. These strains belonged to six species: S. cerevisiae, Candida tropicalis, Candida viswanathii, Wickerhamomyces anomalus, Candida glabrata, and Pichia kudriavzevii. The ability of these strains for improved sugar utilization using seawater-based media was confirmed and, therefore, they could potentially be utilized in fermentations using marine biomass in seawater media, particularly for the production of bioethanol and other biochemical products.

Investigations on a vertical isolation system with quasi-zero stiffness property

  • Zhou, Ying;Chen, Peng
    • Smart Structures and Systems
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    • 제25권5호
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    • pp.543-557
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    • 2020
  • This paper presents a series of experimental and numerical investigations on a vertical isolation system with quasi-zero stiffness (QZS) property. The isolation system comprises a linear helical spring and disk spring. The disk spring is designed to provide variable stiffness to the system. Orthogonal static tests with different design parameters are conducted to verify the mathematical and mechanical models of the isolation system. The deviations between theoretical and test results influenced by the design parameters are summarized. Then, the dynamic tests for the systems with different under-load degrees are performed, including the fast sweeping tests, harmonic excitation tests, and half-sine impact tests. The displacement transmissibility, vibration reduction rate, and free vibration response are calculated. Based on the test results, the variation of the transmission rule is evaluated and the damping magnitudes and types are identified. In addition, the relevant numerical time history responses are calculated considering the nonlinear behavior of the system. The results indicate that the QZS isolation system has a satisfactory isolation effect, while a higher damping level can potentially promote the isolation performance in the low-frequency range. It is also proved that the numerical calculation method accurately predicts the transmission character of the isolation system.

내진시험을 통한 IRB 시스템의 성능 평가 (Performance Evaluation of IRB System Using Seismic Isolation Test)

  • 박영기;하성훈;우제관;최승복;김현
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2013년도 춘계학술대회 논문집
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    • pp.401-406
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    • 2013
  • This paper presents experimental evaluation of IRE (isolation roller bearing) seismic isolation device. From the combination of base isolation on the IRE system displacement response spectrum and acceleration response spectrum, the compressive strength and the coefficient of friction experiments. Also the IRE system is evaluated by environment test according to KS standards. Both the resonance and seismic experiments using a combination of the IRE and Natural Rubber Bearing (NRB) are performed in order to analyze the seismic isolation of the IRE system dynamic characteristics. For the given load and exciting frequency, the resonant frequency becomes lower, but the resonant magnification remains to be same. However, it is shown that when we consider the IRE only, the vibration on the table with the horizontal movement and the independent horizontal displacement due to the rolling motion of the plate and roller are significantly reduced. This result verifies that the proposed optimal design method of the IRE system is very effective.

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Effect of the limiting-device type on the dynamic responses of sliding isolation in a CRLSS

  • Cheng, Xuansheng;Jing, Wei;Li, Xinlei;Lu, Changde
    • Earthquakes and Structures
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    • 제15권2호
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    • pp.133-144
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    • 2018
  • To study the effectiveness of sliding isolation in a CRLSS (concrete rectangular liquid-storage structure) and develop a reasonable limiting-device method, dynamic responses of non-isolation, sliding isolation with spring limiting-devices and sliding isolation with steel bar limiting-devices are comparatively studied by shaking table test. The seismic response reduction advantage of sliding isolation for concrete liquid-storage structures is discussed, and the effect of the limiting-device type on system dynamic responses is analyzed. The results show that the dynamic responses of sliding isolation CRLSS with steel bar-limiting devices are significantly smaller than that of sliding isolation CRLSS with spring-limiting devices. The structure acceleration and liquid sloshing wave height are greatly influenced by spring-limiting devices. The acceleration of the structure in this case is close to or greater than that of a non-isolated structure. Liquid sloshing shows stronger nonlinear characteristics. On the other hand, sliding isolation with steel bar-limiting devices has a good control effect on the structural dynamic response and the liquid sloshing height simultaneously. Thus, a limiting device is an important factor affecting the seismic response reduction effect of sliding isolation. To take full advantage of sliding isolation in a concrete liquid-storage structure, a reasonable design of the limiting device is particularly important.

Rapid identification of Burkholderia glumae from diseased seeds

  • Noh, Tae-Hwan;Song, Wan-Yeob;Kang, Mi-Hyung;Hyung Moo kim;Lee, Du-Ku;Park, Jong-Cheol;Shim, Hyeong-Kwon
    • 한국식물병리학회:학술대회논문집
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    • 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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    • pp.136.1-136
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    • 2003
  • Bacterial grain rot by Burkholderia gluae cause severe damage in seedling and grain of rice after heading season. This seed-borne pathogen play a role as first infection agent that could be cause disease following cropping season. Until now the direct isolation of the bacteria has some trouble by interference of other bacteria existed inside seed. This study established convenient identification method as simple isolation with KB medium from seed showing symptom and using PCR identification. By this isolation method, B. glumae was isolated from 40 to 50% in brown rice and inner hull, however, there were saprophytic bacteria and fungi outer hull. In PCR identification with Ogf4 and Ogr3 primer to these 25 isolates, the amplified products were presented in all of the collections but not in 10 saprophytic germs. The isolation rate was constant to 3 months stored seeds. This result provide a rapid and convenient isolation and identification of B. glumae.

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