• Title/Summary/Keyword: strand type

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Calculation of DC resistance of strand-to-strand joints for KSTAR (KSTAR 용 소선-소선 접합부의 직류저항 계산)

  • Ho-Jin Lee;Hyun-Il Nam;Ki-Baik Kim;Gye-Won Hong
    • Progress in Superconductivity
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    • v.3 no.1
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    • pp.104-110
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    • 2001
  • Since the strand-to-strand type joint far CICC (Cable-In-Conduit Conductor) is small in size and has low DC resistance, it is expected to be useful type fur a superconducting magnet system which had a compact structure like the KSTAR (Korea Superconducting Tokamak Advanced Research) coil system. The DC resistance is changed according to the distribution patterns of strands in cables connected together in the joint. A commercial code was used for the calculation of the DC resistance. With the decrease of outer diameter of the Joint, Which means the increase of strand volume fraction in the joint, the calculated DC resistance decrease rapidly and non-lineally. The variation of resistance depends mainly on the volume fraction of solder which has higher resistivity than copper. The resistance decrease inversely with the increase of the length of the joint. The resistance increase with increase of number of triplets in each stack contacted with that of another terminal cable. In case of the strand-to-strand joint that has 62mm of outer diameter, 52mm of inner diameter, 100mm of overlap length, and four triplets in each stack, the calculated DC resistance is less than 1 n-Ohm.

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DNA Strand Breaks in Mitotic Germ Cells of Caenorhabditis elegans Evaluated by Comet Assay

  • Park, Sojin;Choi, Seoyun;Ahn, Byungchan
    • Molecules and Cells
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    • v.39 no.3
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    • pp.204-210
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    • 2016
  • DNA damage responses are important for the maintenance of genome stability and the survival of organisms. Such responses are activated in the presence of DNA damage and lead to cell cycle arrest, apoptosis, and DNA repair. In Caenorhabditis elegans, double-strand breaks induced by DNA damaging agents have been detected indirectly by antibodies against DSB recognizing proteins. In this study we used a comet assay to detect DNA strand breaks and to measure the elimination of DNA strand breaks in mitotic germline nuclei of C. elegans. We found that C. elegans brc-1 mutants were more sensitive to ionizing radiation and camptothecin than the N2 wild-type strain and repaired DNA strand breaks less efficiently than N2. This study is the first demonstration of direct measurement of DNA strand breaks in mitotic germline nuclei of C. elegans. This newly developed assay can be applied to detect DNA strand breaks in different C. elegans mutants that are sensitive to DNA damaging agents.

Expression of Lily Chloroplastic Cu,Zn Superoxide Dismutase Enhances Resistance to Erwinia carotovora in Potatoes

  • Kim, Mi-Sun;Kim, Hyun-Soon;Kim, Yoon-Sik;Baek, Kwang-Hyun;Moon, Jae-Sun;Choi, Do-Il;Joung, Hyouk;Jeon, Jae-Heung
    • The Plant Pathology Journal
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    • v.23 no.4
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    • pp.300-307
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    • 2007
  • Previously, a chloroplast-localized Cu,Zn superoxide dismutase (chCu,ZnSOD) was isolated from lily and the sense- and antisense- sequences of the lily chCu,ZnSOD were used to transform potato plants. Two selected lines, the sense- and anti-sense strand of transgenic plants, were further characterized for resistance to Erwinia carotovora, which is a severe pathogen affecting potato plants. Only the sense-strand transgenic potato, which contained less $O_2^{.-}$ and more $H_2O_2$ than wild-type and antisense-strand transgenic plants, showed increased resistance to E. carotovora. Additional studies using $O_2^{.-}$ or $H_2O_2$ scavengers in wild-type, sense-strand, and antisense-strand transgenic plants suggest that resistance to E. carotovora is induced by reduced $O_2^{.-}$ and is not influenced by $H_2O_2$. To the best of our knowledge, this report is the first study suggesting that resistance to E. carotovora is enhanced by reduced $O_2^{.-}$, and not by increased amounts of $H_2O_2$.

An Experimental Study on Development Length of Untensioned Prestressing Strand (인장을 가하지 않은 PS강연선의 정착길이에 대한 실험적 연구)

  • Choi, Jun-Young;Ha, Sang-Su;Kim, Seung-Hun;Choi, Chang-Sik;Lee, Li-Hyung
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05a
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    • pp.331-334
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    • 2005
  • The nature of bond of untensioned prestressed strand in concrete differs from that of plain or deformed reinforcing bar as well as tensioned prestressed strand. There is a very limited amount of published research information regarding bonding of this type reinforcing. In order to use and design untensioned strand as reinforcing, relationships defining the load transfer characteristics of the strand are necessary. A program based upon pullout tests was designed to develop data relating the critical parameters for determining load transfer behavior of the untensioned strand. The purpose of this study is to investigate the characteristics of bond and development length between untensioned strand and concrete. The test variables include diameter of strands (9.3mm, 12.7mm) and development lengths. The maximum bond stress at the 9.3mm and 12.7mm strands decreases with the increase of the rate of development length. The untensioned prestressed strands displayed bond performance when secure development length more than 80$\%$ according to the development of deformed bars equation.

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DNA Binding Specificity of Proteus mirabilis Transcription Regulator (Proteus mirabilis 전사 조절 단백질의 DNA 결합 특성)

  • Gang, Jong-Back
    • Korean Journal of Microbiology
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    • v.47 no.2
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    • pp.158-162
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    • 2011
  • Amino acid sequence alignment shows that $\underline{P}$roteus $\underline{m}$irabilis $\underline{t}$ranscription $\underline{r}$egulator (PMTR) has cystein sequence homology at metal binding domain to CueR (copper resistance) protein, which conserves two cysteins (Cys 112 and Cys 120 in PMTR). Gel shift assay revealed that PMTR protein bound to promoter region of Escherichia coli copA (copper-translocating P-type ATPase) and Proteus mirabilis atpase (putative copper-translocating P-type ATPase) genes except that of E. coli zntA (zinc-translocating P-type ATPase) gene. DNase I protection experiment indicated that PMTR protein protected the region over -35 box and close to -10 box. DNase I hypersensitive bases were shown at C and A bases of labeled template strand and at G and C bases of labeled non-template strand of DNA. These hypersensitive bases were appeared in other metalloregulatory proteins of MerR family, which suggests protein-induced DNA bending.

Durability Test on E-Glass Fiber Reinforced Composites of Strand Type in Specific Environment (스트란드형 유리섬유 강화 복합재료의 특수환경에 대한 내구성 시험)

  • Lee Seong-Ryul;Kim By-An;Moon Chang-Kwon
    • Journal of Ocean Engineering and Technology
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    • v.20 no.2 s.69
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    • pp.52-58
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    • 2006
  • The effect of various environmental conditions on the durability of E-glass fiber/vinylester resin composites have been investigated using the tensile test specimen of strand type. It was found that the durability test method performed by the stand type specimen was more convenient and reliable than other conventional test method. The weight gains increased with the immersion time in both water and alkaline solution, and the Weight gains at $50^{\circ}C$. were much bigger than those at $20^{\circ}C$ in both conditions. The tensile strength decreased with the pass of immersion time in all aqueous solution, and the tensile strength at $80^{\circ}C$ in alkaline solution decreased very steeply at beginning of immersion time. The decrement of tensile strength according to the immersion time in various environmental conditions was mainly caused by the degradation of interface and the damage of glass fiber surface.

Study on Characteristics of the $Nb_{3}$Sn Strand for KSTAR Superconducting Magnets (KSTAR 초전도자석용 Nb3Sn 선재 특성 연구)

  • 최현정;김기만;김용진;방성근;윤천석;이재용;김명규;이상일;백설희
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 1999.02a
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    • pp.39-42
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    • 1999
  • The characteristics of Nb3Sn strands shich will be used for the been investigated. The physics requirements for the KSTAR operation demands the two conditions, high non-Cu critical current density and low contradictory to each other. It is recent that superconductor manufacturers. IGC and Mitsubishi, have succeded in the production of the strand which satisfies the ITER HP-1 and HP-2 conditions at the same time. It has been determined that this type of strand, so-called HP-3, will be used for the KSTAR magnets and its properties, critical current density and hysteresis loss investigated by the several institutes are presented here. On the basis of the round robin tests for many strand samples under various optimized and the vendor will be seleted.

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An Experimental Study on Tensile Characteristics for Strand Type FRP Tendon in Development (개발중인 스트랜드형 FRP 긴장재의 인장특성에 관한 실험적 연구)

  • Jung, Woo-Tai;Lee, Seung-Joo;Park, Young-Hwan;Hwang, Geum-Sic
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.11a
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    • pp.809-812
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    • 2006
  • This paper presents the results of tensile characteristics for developing FRP tendon with strand type. The performance targets were decided to compare the tensile characteristics of developing FRP tendon. Test specimens were manufactured by applying some improvements to enhance the tensile characteristics. The influence factors on the tensile characteristics have been found from the test results. Those are the fiber weight fraction, the pitch, the FRP cross sectional area, and the type of external fibers. The tensile characteristics were satisfactory compared to the performance targets.

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Genetic Differentiation of Phytoplasma Isolates by DNA Heteroduplex Mobility Assay and Single-Strand Conformation Polymorphism Analysis

  • Cha, Byeongjin;Han, Sangsub
    • The Plant Pathology Journal
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    • v.18 no.6
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    • pp.308-312
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    • 2002
  • Heteroduplex mobility assay (HMA) and single-strand conformation polymorphism (SSCP) analyses combined with PCR were developed for genetic differentiation of various phytoplasma isolates. In the HMA and SSCP analyses, differences in the mobility shifts and the SSCP band patterns identified three distinct types of phyto-plasmas: Type Ⅰ, jujube witches'-broom (JWB) and ligustrum witches'-broom (LiWB); Type Ⅱ, mulberry dwarf(MD) and sumac witches'-broom (SuWB); and Type Ⅲ, paulownia witches'-broom (PaWB). Results of the sequence analyses revealed that phytoplasmas of JWB and MD had 100% homology with LiWB and SuWB, respectively. On the other hand, PaWB phyto-plasma had 97.8% homology with MD phytoplasma. The PCR-HMA and SSCP techniques were very useful in determining variations in sequence among several isolates of phytoplasmas. Furthermore, the methods were rapid, economical, highly sensitive, and easy to handle with the gels.