• Title/Summary/Keyword: Hinge region

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Experimental Behavior of Reinforced Concrete Column-Bent Piers under Bidirectional Repeated Loading (이축반복하중을 받는 2주형 철근콘크리트 교각의 실험거동)

  • Park, Chang-Kyu;Lee, Beom-Gi;Song, Hee-Won;Chung, Young-Soo
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.1 s.41
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    • pp.17-24
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    • 2005
  • Response of reinforced concrete (RC) column-bent piers subjected to bidirectional seismic loadings was experimentally investigated. RC column-bent piers represent one of the most popular shapes of piers used in Korea highway bridges. Four column-bent piers were constructed in 400 mm diameter and 2,000 mm height. Each pier has two circular supporting columns. These piers were tested under bidirectional lateral load reversals with an axial load of $0.1f_{ck}A_g$. The test parameters included : different transverse reinforcement contents and lap-spliced longitudinal reinforcing steels. Test results indicate that the lap splice of longitudinal reinforcing steels have significantly influenced on hysteretic response of column-bent piers similar to previous test results for single columns with corresponding test parameters. Column capacity was changed with the level of transverse confinement. From the comparison of test result for single column under unidirectional loading, the damage of single column was concentrated on lower plastic hinge region but the damage of column-bent piers was scattered to upper and lower plastic hinge region.

Activities of different cysteine proteases of Pcrogonimn westermani in cleaving human IgG (발육단계별로 정제한 폐흡충 시스테인계열 단백분해효소의 IgG 분해양상)

  • 정영배;양현종
    • Parasites, Hosts and Diseases
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    • v.35 no.2
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    • pp.139-142
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    • 1997
  • Cleaving host immunoglobulins is a well known mechanism of evading host immune reactions exploited by helminth parasites, Secreted cysteine proteases of helminth are a part of enzymes cleaving host IgG. Porogonimw westemani produces at least six different species of the cysteine protease in its developmental stages. This study was undertaken to evaluate comparatively the activities against human IgG by the different enzymes. When the metacercariae, which secrete 27 and 28 kDa cysteine proteases, were incubated in human IgG solution, IgG was degraded at its hinge region. Further incubation resulted complete hydrolysis. From 4-week and 7-week old juveniles and 16-week old adults of p. westemani, five different enzymes at 15, 17. 27 28 and 53 kDa have been purified, if the enzyme with the same molecular mass is regarded to be identical. In cleaving human IgG, each cysteine protease exhibited decreasing activities with age.

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Seismic Performance Enhancement of Reinforced Concrete Bridge Piers wrapped with Prestressed Steel Jacket by the Quasi-Static Test (프리스트레스트된 강판으로 보강된 철근콘크리트 교각의 준정적 실험에 의한 내진 성능 향상 연구)

  • Choel, Beak-Min;Chung, Young-Soo;Choi, Eun-Soo;Yang, Dong-Wook
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.77-80
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    • 2008
  • Lap splices were located in the plastic hinge region of most bridge piers that were constructed before the adoption of the seismic design provision of Korea Highway Design Specification on 1992. This research aims at evaluating the seismic performance of reinforced concrete bridge piers with lap-spliced longitudinal steels, which were strengthened with prestressed steel jacket in the plastic hinge region. Quasi-static test was used to investigate the seismic performance enhancement of RC test specimens. Conventional method applied mortar grouting inside steel jacket, but this research did not apply mortar grouting inside steel plate. Four test specimens in an aspect of 3.5 were constructed with 400 mm in diameter and 1600 mm in height. Test parameters are the lap splice of longitudinal reinforcing steels and thickness of steel jacket.

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Seismic-performance Flexural Experiments for Real Scale Piers with Circular Cross-section Considering Aging Effects (노후도를 고려한 실크기 원형단면 교각의 내진성능 휨실험)

  • Lee, Seung-Geon;Lee, Soo-Hyung;Lee, Hyerin;Hong, Kee-Jeung
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.6
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    • pp.131-142
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    • 2021
  • For old piers constructed when seismic design code had not been developed, lap splices usually exist in plastic hinge region. Corrosion of rebars causes decreasement in cross-sectional area of rebar and deterioration of lap-splice behaviour, thereby reducing the seismic performance of the old piers. In this research, according to these characteristics of old piers, test specimens are designed and manufactured considering rebar corrosion, lap splice, seismic design details, and seismic reinforcement. These effects are investigated through experiments. As a result of these experiment, rebar corrosion as well as lap splice reduces displacement ductility. When seismic design details or steel-plate reinforcement are applied, sufficient displacement ductility is expressed. For non-seismically designed specimens, loosening of the lap splice of transverse rebars caused buckling of longitudinal rebars and crushing of core concrete in plastic hinge region . For seismically designed specimen, area-reducing and untying of transverse rebars due to corrosion of rebars caused buckling of longitudinal rebars and crushing of core concrete.

Pseudo Dynamic Test Research on the Seismic Performance of RC Bridge Piers Retrofitted with Fiber Sheet (섬유보강 RC교각의 내진성능에 관한 유사동적실험 연구)

  • 박종협;박희상;정영수
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.559-564
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    • 2001
  • The objective of this experimental research is to assess the seismic performance of circular RC bridge pier specimens retrofitted with fibers which were designed as a prototype of Hagal bridge in the city of Suwon, Korea. Pseudo-dynamic test has been done for two nonseismic test specimens which were nonseismic designed by the related provisions of the Highway Design Specification, and four nonseismic test specimens retrofitted with fibers in the plastic hinge region. Important test parameters were load patterns, and retrofit. The seismic behavior has been analyzed through the displacement ductility, energy analysis, and capacity spectrum. Approximate 7.0 displacement ductility was observed for nonseismic test specimens retrofitted with fibers. It is concluded that these retrofitting test specimens could have sufficient seismic capacity in the region of moderate seismic zone.

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Quasi-Static Test for Seismic Performance of R/C Bridge Piers Retrofitted with Glassfibers (준정적실험에 의한 섬유보강된 철근콘크리트 교각의 내진성능 평가)

  • 이대형;이재형;정영수;박진영
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.871-876
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    • 2001
  • Recent earthquakes in California and Japan caused extensive damage to highway bridge structures. It is also thought that during probable earthquakes bridge structures in Korea could be failed due to the structural deficiencies, which were nonseismically designed and constructed before 1992. In these regards, innovative strengthening methods have been developed to repair reinforced concrete bridge columns, especially by glassfiber sheet bonding methods which are widely used today. The primary objective of this research is to investigate the seismic behavior of RC bridge columns retrofitted with composite straps and to propose pertinent guidelines of repair and rehabilitation method for earthquake resistant design procedure of RC bridges which are located in low or moderate seismicity regions. Six scaled-down concrete test specimens were made with test variables such as lap splice ratio, axial force ratio, confinement ratio, composite straps in the plastic hinge region. Pertinent design guidelines could be developed for the earthquake resistant design of RC bridge piers retrofitted with glassfibers in low or moderate seismic region.

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Construction and Characterization of a Single-Chain Immunoglobulin

  • Kim, Youn-Kyu;Choi, In-Hak;Ryu, Chun-Jeih;Hong, Hyo-Jeong
    • BMB Reports
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    • v.30 no.3
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    • pp.177-181
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    • 1997
  • We constructed a single-chain immunoglobulin in which the carboxyl end of the heavy chain variable domain is covalently joined to the amino terminus of the light chain variable domain via peptide linker and the carboxyl end of the light chain variable domain is linked to human ${\gamma}1$ Fc region through the hinge region. The molecule was expressed in Chinese hamster ovary cells, assembled into a dimeric molecule and secreted into the culture medium. The dimeric molecule (2E11) was purified from the culture supernatant by affinity chromatography on Protein G-Sepharose column. The size of the unreduced or reduced protein was the expected molecular weight of approximately 120 or 60 kDa, respectively, as assessed by SDS-polyacrylamide gel electrophoresis. The antigen-binding affinity of 2E11 was almost the same as that of a native antibody counterpart (CS131A), suggesting that the single-chain immunoglobulin may function like a native antibody.

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Fundamental behavior of CFT beam-columns under fire loading

  • Varma, Amit H.;Hong, Sangdo;Choe, Lisa
    • Steel and Composite Structures
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    • v.15 no.6
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    • pp.679-703
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    • 2013
  • This paper presents experimental investigations of the fundamental behavior of concrete filled steel tube (CFT) beam-columns under fire loading. A total of thirteen specimens were tested to determine the axial force-moment-curvature-temperature behavior of CFT beam-columns. The experimental approach involved the use of: (a) innovative heating and control equipment to apply thermal loading and (b) digital image correlation with close-range photogrammetry to measure the deformations (e.g., curvature) of the heated region. Each specimen was sequentially subjected to: (i) constant axial loading; (ii) thermal loading in the expected plastic hinge region following the ASTM E119 temperature-time T-t curve; and (iii) monotonically increasing flexural loading. The effects of various parameters on the strength and stiffness of CFT beam-columns were evaluated. The parameters considered were the steel tube width, width-tothickness ratio, concrete strength, maximum surface temperature of the steel tube, and the axial load level on the composite CFT section. The experimental results provide knowledge of the fundamental behavior of composite CFT beam-columns, and can be used to calibrate analytical models or macro finite element models developed for predicting behavior of CFT members and frames under fire loading.

Cyclic AMP Receptor Protein Adopts the Highly Stable Conformation at Millimolar cAMP Concentration (높은 cAMP 농도에서 cAMP 수용성 단백질의 열 안정화)

  • Kang, Jong-Baek;Choi, Young
    • Journal of Life Science
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    • v.13 no.5
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    • pp.751-755
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    • 2003
  • Cyclic AMP receptor proteins(CRP) activate many genes in Escherichia coli by binding of cAMP with not fully known mechanism. CRP existed as apo-CRP in the absence of cAMP, $CRP;(cAMP)_2$$_2$ at low(micromolar) cAMP concentration, or $CRP;(cAMP)_4$ at high(millimolar) concentration of cAMP. This study is designed to measure the thermal stability of S83G CRP, which substituted glycine for serine at amino acid 83 position, with CD spectrapolarimeter at 222nm by the constant elevation of temperature from $20^{\circ]C\; to\; 90^{\circ}C\; at\; 1^{\circ}C/min$. The non-linear regression analysis showed that melting temperatures were 68.4, 72.0, and $82.3^{\circ}C$ for no cAMP, 0.1mM cAMP, and 5mM cAMP, respectively. Result showed the strong thermal stability of CRP by binding of additional cAMP molecules to region between the hinge region and helix-turn-helix(HTH) motif at 5mM cAMP concentration.

Development of Natural Dyeing Pigments and Culture Goods with Useful Biological Resources - Research on Development of Tourist Souvenirs for Hampyeong Butterfly Festival - (유용생물자원을 이용한 천연염료의 개발 및 문화상품전개 - 함평나비축제를 위한 관광기념품 개발에 관한 연구중심으로 -)

  • Park, Mi-Ryung;Kim, Sang-Yool
    • Fashion & Textile Research Journal
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    • v.8 no.6
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    • pp.665-671
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    • 2006
  • This study is to develop tourist souvenir which designed image of butterfly, the symbol of Hampyeong Butterfly Festival, using natural dyeing product, the specialty of Namdo region. Results of market survey of tourist souvenirs for Hampyeong Butterfly festival showed that souvenirs of butterfly design sold in market which were not discriminated from that of general products and locality or characteristic of the region could not be exhibited. According to the results of market survey, design of souvenirs of Hampyeong Butterfly Festival is as follows; Butterfly pattern of hinge and Dangcho pattern are developed to graphic motive of modern sense with traditional beauty to make design which can be consumed by modern consumers in their actual life and then proper pattern is planned by combining, repeating and disassembling them. Such a pattern is applied to souvenirs like T-shirts, necktie and scarf to make tourists feel identity and unification of the festival visually. In addition, design of souvenirs was made to be coordinated with casuals. Therefore, visual factor could be extracted from Korean cultural heritages suitable to concept of local festivals and it is considered that ways of commercialization and development of traditional pattern suitable to consumers' demands can be suggested.