• Title/Summary/Keyword: line resistance

Search Result 1,381, Processing Time 0.027 seconds

A Study on Adaptive Distance Protection of Double-circuit Line with Mutual Impedance and Fault Resistance (2회선 송전선로에서 상호임피던스와 고장저항을 고려한 거리계전기의 동작 특성 연구)

  • 이원석;정창호;김진오
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.53 no.4
    • /
    • pp.221-226
    • /
    • 2004
  • Power system has recently used Double-circuit Line and Multi-circuit Line in the industrial development. This has an advantage of system stability and reliability, but the complexity of the system has a disadvantage that makes it difficult to protect the power line. Double-circuit Line has two operation conditions in the Single-circuit operation and Double-circuit operation, so it has mutual impedance. To make it possible for the remaining single-line to operate independently while there is a fault with first line or when maintenance is needed, a trip region for the single-circuit operation should be set in order to set the relay trip region. An optimal trip region for each operation, a different operational conditions for the relay setting should be calculated. In this paper, trip regions of each operation condition have been compared by considering mutual impedance and fault resistance that led to the calculation of fault impedance. Also, as we know that one of the advantages in the distance relay is the back-up protection, we calculated the trip region(Zone-2) in consideration of the mutual impedance.

A Study on Adaptive Distance Protection of Double-circuit Line with Mutual Impedance and Fault Resistance (2회선 송전선로에서 상호임피던스와 고장저항을 고려한 거리계전기의 동작 특성 연구)

  • 이원석;정창호;김진오
    • The Transactions of the Korean Institute of Electrical Engineers B
    • /
    • v.53 no.4
    • /
    • pp.221-221
    • /
    • 2004
  • Power system has recently used Double-circuit Line and Multi-circuit Line in the industrial development. This has an advantage of system stability and reliability, but the complexity of the system has a disadvantage that makes it difficult to protect the power line. Double-circuit Line has two operation conditions in the Single-circuit operation and Double-circuit operation, so it has mutual impedance. To make it possible for the remaining single-line to operate independently while there is a fault with first line or when maintenance is needed, a trip region for the single-circuit operation should be set in order to set the relay trip region. An optimal trip region for each operation, a different operational conditions for the relay setting should be calculated. In this paper, trip regions of each operation condition have been compared by considering mutual impedance and fault resistance that led to the calculation of fault impedance. Also, as we know that one of the advantages in the distance relay is the back-up protection, we calculated the trip region(Zone-2) in consideration of the mutual impedance.

Fault Location Algorithm in Parallel Transmission Line Using Zero Sequence Network (영상회로를 이용한 병행 송전선로에서의 고장점 추정 알고리즘)

  • Park, Hong-Kyu;Lee, Jae-Gyu;You, Seok-Ku
    • Proceedings of the KIEE Conference
    • /
    • 1999.11b
    • /
    • pp.282-284
    • /
    • 1999
  • This paper presents an accurate algorithm for fault location of a single phase to earth fault on a two-parallel transmission line using only one-terminal data. It is impossible to calculate the accurate fault distance, because of the unknown fault resistance and fault current at the fault point. The faulted line circuit and the zero-sequence circuit of two-parallel line are used as a fault location model, which the source impedance of the remote end is not involved. The algorithm can eliminate the effect of load flow and the fault resistance in calculating the fault location.

  • PDF

Selection in $F_3$ and $F_4$ Generations of a Cross for Breeding Genic Male Sterile Pepper Lines Resistant to Phytophthora Blight and Bacterial Spot (역병과 세균성점무늬병에 복합저항성인 핵유전형 웅성불임성 고추 계통 육성을 위한 교배의 $F_3-F_4$세대 선발)

  • Park, Dong-Keun;Kim, Byung-Soo
    • Current Research on Agriculture and Life Sciences
    • /
    • v.28
    • /
    • pp.17-23
    • /
    • 2010
  • Selection procedures for breeding genic male sterile lines for resistance to both Phytophthora blight caused by Phytophthora capsici and bacterial spot caused by Xanthomonas euvesicatoria were executed to $F_3$ and $F_4$ generations derived from a cross between a Phytophthora resistant genic male sterile (GMS) breeding line and a bacterial spot and Phytophthora resistant breeding line. Resistance to P. capsici was originally introduced from KC294(CM334) and KC263(AC2258), the well-known sources of resistance to P. capsici. Resistance to bacterial spot was introduced from KC47(PI244670). GMS lines with high resistance to P. capsici were obtained and the selected lines are expected to be quantitatively resistant also to bacterial spot.

  • PDF

Influence of Ribosomal Protein L39-L in the Drug Resistance Mechanisms of Lacrimal Gland Adenoid Cystic Carcinoma Cells

  • Ye, Qing;Ding, Shao-Feng;Wang, Zhi-An;Feng, Jie;Tan, Wen-Bin
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.15 no.12
    • /
    • pp.4995-5000
    • /
    • 2014
  • Background: Cancer constitutes a key pressure on public health regardless of the economy state in different countries. As a kind of highly malignant epithelial tumor, lacrimal gland adenoid cystic carcinoma can occur in any part of the body, such as salivary gland, submandibular gland, trachea, lung, breast, skin and lacrimal gland. Chemotherapy is one of the key treatment techniques, but drug resistance, especially MDR, seriously blunts its effects. As an element of the 60S large ribosomal subunit, the ribosomal protein L39-L gene appears to be documented specifically in the human testis and many human cancer samples of different origins. Materials and Methods: Total RNA of cultured drug-resistant and susceptible lacrimal gland adenoid cystic carcinoma cells was seperated, and real time quantitative RT-PCR were used to reveal transcription differences between amycin resistant and susceptible strains of lacrimal gland adenoid cystic carcinoma cells. Viability assays were used to present the amycin resistance difference in a RPL39-L transfected lacrimal gland adenoid cystic carcinoma cell line as compared to control vector and null-transfected lacrimal gland adenoid cystic carcinoma cell lines. Results: The ribosomal protein L39-L transcription level was 6.5-fold higher in the drug-resistant human lacrimal gland adenoid cystic carcinoma cell line than in the susceptible cell line by quantitative RT-PCR analysis. The ribosomal protein L39-L transfected cells revealed enhanced drug resistance compared to plasmid vector-transfected or null-transfected cells as determined by methyl tritiated thymidine (3H-TdR) incorporation. Conclusions: The ribosomal protein L39-L gene could possibly have influence on the drug resistance mechanism of lacrimal gland adenoid cystic carcinoma cells.

Effects of the Position of Potential Probe on Ground Resistance Measurements Using the Fall-of-Potential Method (전위강하법에 의한 접지저항측정에 미치는 전위보조전극 위치의 영향)

  • 이복희;어주홍;김성원
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.15 no.2
    • /
    • pp.97-104
    • /
    • 2001
  • The effects of the position of potential probe on the measurements of the ground resistance in the fa11-of-potential method are described. The ground resistance is theoretically calculated by applying the 61.8[%] rule, and then the potential probe is located on the straight line between the grounding electrode to be measured and the current probe. However, sometimes the grounding electrode to be measured and the measuring potential and current probes in on-site test might not be arranged on the straight line with adequate distance because there are building, roadblock construction and other establishments. Provided that the grounding electrode to be measured and the measuring potential probes are out of position on the straight line, the measurement of the ground resistance classically falls into an error and the measured ground resistance should be corrected. In this work, measurements were focused on the grounding electrode system made by the ground rods of 2.4 m long. The measuring error was increased with increasing the angle which is made by the 3-points of the grounding electrode to be measured, the potential anti current probes, and it was a negative. That is, all of the measured ground resistances ware less than the true ground resistance.

  • PDF

Optimal First-line Eradication Regimens for Helicobacter pylori Infection in Patients with Clarithromycin Resistance: A Pilot Study (국내 클래리스로마이신 내성균에서 가장 효과적인 헬리코박터 제균 치료법)

  • Seo, Min Woo;Jeong, Yeon Jeong;Kim, Joon Sung;Kim, Byung Wook
    • The Korean journal of helicobacter and upper gastrointestinal research
    • /
    • v.18 no.4
    • /
    • pp.242-246
    • /
    • 2018
  • Background/Aims: Helicobacter pylori eradication rates using first-line treatment have decreased due to clarithromycin resistance. The aim of this study was to investigate optimal eradication regimens for patients with clarithromycin resistance in Korea. Materials and Methods: A total of 72 patients with confirmed clarithromycin resistance were enrolled from August 2015 to July 2017. Patients were randomized to a 7-day bismuth quadruple therapy (BQT) regimen or a 7-day metronidazole triple therapy (MTT) regimen. Eradication was confirmed using the $^{13}C$-urea breath test. Results: There were no differences in baseline characteristics between the groups. Intention-to-treat eradication rates were 77.8% for the BQT group and 66.7% for the MTT group (P=0.293). Per protocol eradication rates were 87.5% for the BQT group and 77.4% for the MTT group (P=0.292). Adverse events were more frequent in the BQT group. Conclusions: Eradication rates using MTT were comparable to those using BQT, and adverse events were less frequent in the MTT group. Thus, MTT may be considered as a first-line regimen for patients with clarithromycin resistance. Since this was a pilot study, a study with a large group is required.

Low-resistance W Bit-line Implementation with RTP Anneal & Additional ion Implantation (RTP 어닐과 추가 이온주입에 의한 저-저항 텅스텐 비트-선 구현)

  • Lee, Yong-Hui;Lee, Cheon-Hui
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.38 no.5
    • /
    • pp.375-381
    • /
    • 2001
  • As the device geometry continuously shrink down less than sub-quarter micrometer, DRAM makers are going to replace conventional tungsten-polycide bit-line with tungsten bit-line structure in order to reduce the chip size and use it as a local interconnection. In this paper we showed low resistance tungsten bit-line fabrication process with various RTP(Rapid Thermal Process) temperature and additional ion implantation. As a result we obtained that major parameters impact on tungsten bit-line process are RTP Anneal temperature and BF$_2$ ion implantation dopant. These tungsten bit-line process are promising to fabricate high density chip technology.

  • PDF

Characteristics of A New Flue-cured Tobacco Mutant Line KF 8832-85 (황색종 연초 돌연변이 계통 KF8832-85의 특성)

  • 조수헌
    • Journal of the Korean Society of Tobacco Science
    • /
    • v.17 no.1
    • /
    • pp.27-32
    • /
    • 1995
  • A new flue-cured tobacco mutant line BU 8832-85 was developed at Taegu Experiment Station, Korea Ginseng and Tobacco Research Institute in 1994. KF 8832-85 was resulted from a cross of flue-cured cultivars NC 95$\times$NC 2326, and developed by a pedigree system of breeding ; initial selection was made by plant type and resistance to bacterial wilt(BW) disease(heudomonas solanaceamm) in the F2 generation under the natural field conditions infested with the pathogen. One white flowered plant was occurred by spontaneous mutation in a certain line among the F3 generatioin while the others were pink. Six plants from the seeds by selfing were selected at the field infested with the pathogen among 240 populations with white flowering in the F4, KF 8832-85 was selected based on yield and leaf quality trials among 6 lines in Fs generation. BCF 8832-85 was compared with its Parent for certain agronomic and chemical characteristics at Taegu Experiment Station in 1993 and 1994. The results showed that KF 8832-85 have white flower, the stalk height was approximately that of NC 2326 but averaged about loom taller than NC 95. It produced ground suckers as much as NC 95, and did not breakdown leaf at the same as WC 2326. KF 8832-85 have high resistance to bacterial wilt disease. Yield of KF 8832-85 was 10 and 18% higher then that of NC 2326 and WC 95, respectively. Price per Kg was equal to that of NC 2326. The contents of nicotine and reducing sugar did not differ significantly from NC 95, while total nitrogen was significantly lower than NC 95. Therefore, the new mutant line is genetically stable for agronomic and chemical characteristics and provides a source of bacterial wilt disease resistance for use in breeding resistant flue-cured cultivars. Key words : Mutant line, White flower, Spontaneous mutation.

  • PDF

Mechanistic Analysis of Taxol-induced Multidrug Resistance in an Ovarian Cancer Cell Line

  • Wang, Ning-Ning;Zhao, Li-Jun;Wu, Li-Nan;He, Ming-Feng;Qu, Jun-Wei;Zhao, Yi-Bing;Zhao, Wan-Zhou;Li, Jie-Shou;Wang, Jin-Hua
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.14 no.9
    • /
    • pp.4983-4988
    • /
    • 2013
  • Objectives: To establish a taxol-resistant cell line of human ovarian carcinoma (A2780/Taxol) and investigate its biological features. Methods: The drug-resistant cell line (A2780/Taxol) was established by continuous stepwise selection with increasing concentrations of Taxol. Cell morphology was assessed by microscopy and growth curves were generated with in vitro and in vivo tumor xenograft models. With rhodamine123 (Rh123) assays, cell cycle distribution and the apoptotic rate were analyzed by flow cytometry (FCM). Drug resistance-related and signal associated proteins, including P-gp, MRPs, caveolin-1, PKC-${\alpha}$, Akt, ERK1/2, were detected by Western blotting. Results: A2780/Taxol cells were established with stable resistance to taxol. The drug resistance index (RI) was 430.7. Cross-resistance to other drugs was also shown, but there was no significant change to radioresistance. Compared with parental cells, A2780/Taxol cells were significantly heteromorphous, with a significant delay in population doubling time and reduced uptake of Rh123 (p<0.01). In vivo, tumor take by A2780 cells was 80%, and tumor volume increased gradually. In contrast, with A2780/Taxol cells in xenograft models there was no tumor development. FCM analysis revealed that A2780/Taxol cells had a higher percentage of G0/G1 and lower S phase, but no changes of G2 phase and the apoptosis rate. Expression of P-gp, MRP1, MRP2, BCRP, LRP, caveolin-1, PKC-${\alpha}$, Phospho-ERK1/2 and Phospho-JNK protein was significantly up-regulated, while Akt and p38 MARK protein expression was not changed in A2780/Taxol cells. Conclusion: The A2780/Taxol cell line is an ideal model to investigate the mechanism of muti-drug resistance related to overexpression of drug-resistance associated proteins and activation of the PKC-${\alpha}/ERK$ (JNK) signaling pathway.