• 제목/요약/키워드: Well resistance

검색결과 3,073건 처리시간 0.029초

Shear strength of connections between open and closed steel-concrete composite sandwich structures

  • Kim, Woo-Bum;Choi, Byong Jeong
    • Steel and Composite Structures
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    • 제11권2호
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    • pp.169-181
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    • 2011
  • The behavior of connections between open sandwich slabs and double steel skin composite walls in steel plate-concrete(SC) structure is investigated by a series of experimental programs to identify the roles of components in the transfer of forces. Such connections are supposed to transfer shear by the action of friction on the interface between the steel surface and the concrete surface, as well as the shear resistance of the bottom steel plate attached to the wall. Experimental observation showed that shear transfer in slabs subjected to shear in short spans is explained by direct force transfer via diagonal struts and indirect force transfer via truss actions. Shear resistance at the interface is enhanced by the shear capacity of the shear plate as well as friction caused by the compressive force along the wall plate. Shear friction resistance along the wall plate was deduced from experimental observation. Finally, the appropriate design strength of the connection is proposed for a practical design purpose.

345kV 지중 및 혼합 송전계통에서의 개폐 과전압 해석 (Analysis of Switching Overvoltage in 345kV Underground and Combined Transmission Systems)

  • 정채균;이종범;강지원
    • 대한전기학회논문지:전력기술부문A
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    • 제52권12호
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    • pp.713-721
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    • 2003
  • This paper analyzes the switching overvoltage occurred on 345kV underground power cable system as well as combined transmission system using EMTP. Cable length and closing time, preinsertion resistance have effect on switching overvoltage. Therefore, this paper analyzes the switching overvoltage occurred on conductor and sheath with change of those parameters. Specially, the cross bonding position becomes discontinuity point because of the difference between surge impedance of metal sheath and that of lead cable. Thus, the transmission and the reflection of traveling wave complexly occur at this connection point. According to these influences, voltage between sheath and earth as well as voltage between joint boxes rise. Time to crest point of switching overvoltage is longer than lightning overvoltage. Even though the voltage induced by switching surge is smaller than lightning surge, that voltage may have serious effect on the metal sheath. Therefore, this paper also analyses the reduction effect of switching overvoltage when the preinsertion resistance of circuit breaker is considered.

방균실란트의 방균지속성 평가 (Antifungal Durability Evaluation of Sanitary Sealant)

  • 서연원;정진영;안명수;김성현;배기선
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2014년도 추계 학술논문 발표대회
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    • pp.65-67
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    • 2014
  • There are many elastomeric joint sealant applications in construction such as structural glazing, weatherproofing and insulating glass fabrication etc. Each sealant joints require unique durability functions to perform well through building life cycle. Elastomeric joints in bathroom and kitchen is one of areas which require durable sealing. In this application, anti fungal durability is proprietary function of sealant during building life cycle. Premature failure of anti fungus resistance of sealant is putting big stresses to general contractor as well as the inhabitants due to costly rework and poor sanitation. Accordingly, when chemists design a product, they must take into account various parameters not only formulation components also test conditions in order to have long term fungal durability. This paper reviews several biocide options with various industry standards for fungus resistance performance to suggest making new test method for construction sealant industry.

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Advanced Metallic Coating for the Improvement of Corrosion and Erosion Resistance of Iron Base Materials Used in Buildings and Special Works

  • Jayaraj, J.;Seok, H.K.;Byun, K.H.;Fleury, E.;Hong, K.T.
    • Corrosion Science and Technology
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    • 제4권2호
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    • pp.64-68
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    • 2005
  • Various metallic materials are coated on Fe base materials via thermal spraying or welding process to improve both corrosion resistance as well as erosion resistance of the Fe base materials used in buildings and special works. The mechanical properties and corrosion resistance of the coat are estimated by means of hardness measurement and anodic polarization test. In additions, the effect of alloying elements and microstructure of the coatings on the mechanical and chemical properties of the coat is investigated using X- ray diffraction, Optical microscope, Transmission electron microscopy and Auger analysis. The coating deposited by tungsten inert gas (TIG) welding exhibit a good combination of hardness and corrosion properties.

The Hypersensitive Response. A Cell Death during Disease Resistance

  • Park, Jeong-Mee
    • The Plant Pathology Journal
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    • 제21권2호
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    • pp.99-101
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    • 2005
  • Host cell death occurs during many, but not all, interactions between plants and the pathogens that infect them. This cell death can be associated with disease resistance or susceptibility, depending on the nature of the pathogen. The most well-known cell death response in plants is the hypersensitive response (HR) associated with a resistance response. HR is commonly regulated by direct or indirect interactions between avirulence proteins from pathogen and resistance proteins from plant and it can be the result of multiple signaling pathways. Ion fluxes and the generation of reactive oxygen species commonly precede cell death, but a direct involvement of the latter seems to vary with the plant-pathogen combination. Exciting advances have been made in the identification of cellular protective components and cell death suppressors that might operate in HR. In this review, recent progress in the mechanisms by which plant programmed cell death (PCD) occurs during disease resistance will be discussed.

저항 점용접의 1차 회로 동저항 모니처링에 관한 연구 (Dynamic Resistance Monitoring in Primary Circuit during Resistatnce Spot Welding)

  • 조용준;황정복;신현일;배경민;권태용;이세헌
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 1998년도 특별강연 및 추계학술발표 개요집
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    • pp.129-132
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    • 1998
  • The dynamic resistance monitoring in primary circuit or T/C is one of the important issues in that in-process and real time quality assurance of resistance spot weld is needed to increase the product reliability. It is well known that tile dynamic resistance curve gives us very useful information about nugget growth and weldability. In the present paper, a new dynamic resistance detecting method is presented as a practical manner of weld quality assurance using instantaneous current and voltage measured by primary circuit. Primary dynamic resistance patterns are basically similar to those of the secondary, but there is evident advantage such as no extra devices are needed to obtain the quality assurance index and eventually feedback control will be possible caused by T/C based monitoring system.

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Multidrug Resistance-Associated Protein 1 Predicts Relapse in Iranian Childhood Acute Lymphoblastic Leukemia

  • Mahjoubi, Frouzandeh;Akbari, Soodeh
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권5호
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    • pp.2285-2289
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    • 2012
  • Multidrug resistance (MDR) is a main cause of failure in the chemotherapeutic treatment of malignant disorders. One of the well-known genes responsible for drug resistance encodes the multidrug resistance-associated protein (MRP1). The association of MRP1 with clinical drug resistance has not systematically been investigated in Iranian pediatric leukemia patients. We therefore applied real-time RT-PCR technology to study the association between the MRP1 gene and MDR phenotype in Iranian pediatric leukemia patients. We found that overexpression of MRP1 occurred in most Iranian pediatric leukemia patients at relapse. However, no relation between MRP1 mRNA levels and other clinical characteristics, including cytogenetic subgroups and FAB subtypes, was found.

Sources of Resistance to Bacterial Wilt Found in Vietnam Collections of Pepper (Capsicum annuum) and Their Nuclear Fertility Restorer Genotypes for Cytoplasmic Male Sterility

  • Tran, Ngoc Hung;Kim, Byung-Soo
    • The Plant Pathology Journal
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    • 제28권4호
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    • pp.418-422
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    • 2012
  • Eleven hot pepper accessions collected in Vietnam showed stable resistance to bacterial wilt as well-known resistance sources, MC4 and MC5, in repeated inoculation tests with different Ralstonia solanacearum isolates conducted from 2004 to 2010. Seven of these accessions (specifically KC981, KC1006, KC1021, KC1027, KC1045, KC1050, and KC1055) resulted in stable male sterile F1 plants in the crosses with a cytoplasmically male sterile (CMS) Chilseong (CMS-A, Srfrf ), and therefore, they were maintainers (CMS-B) with a genotype of Nrfrf. The rest (KC980, KC995, KC999, and KC1009) produced stable male fertile F1 plants in the crosses, and therefore, were restorers (CMS-C) with a genotype of N(S)RfRf. Therefore, the maintainer and restorer sources of resistance may be used in preference in breeding maternal (CMS and their maintainers) and paternal parents (restorers) for resistance to bacterial wilt, respectively, in the hybrid breeding system utilizing cytoplasmic male sterility.

버팀재 볼트 접합형 강재스트립 보강재의 인발거동특성 평가 (An Evaluation of Pullout Behavior Characteristics of the Steel Strip Reinforcement Bolted with Braced Angles)

  • 김홍택;방윤경;정중섭;박시삼;김현조
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2002년도 가을 학술발표회 논문집
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    • pp.419-426
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    • 2002
  • In this study, the steel strip reinforcement bolted with braced angles is displayed skin friction resistance as well as passive resistance through existing the steel strip reinforcement. To understand pullout behavior characteristics, friction effects between soil and reinforcement are evaluated with the width of reinforcement, magnitude of surcharge, and existence of passive resistance member through laboratory pullout test. To analyze interference effects for passive resistance member, various tests are carried on case that the number, the location, and the spacing of braced angles are different. Using this test result, pullout resistance factor is calculated to consider location of braced angles and degree of interference for spacing ratio.

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전기 저항을 이용한 실접촉 면적과 윤활 영역의 예측 (Estimation of Real Area of Contact and Lubrication Regimes using Electric Contact Resistance)

  • 이홍철;김대은
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 2000년도 제32회 추계학술대회 정기총회
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    • pp.11-17
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    • 2000
  • The electric contact resistance between ball and disk was measured to estimate the real area of contact under dry and lubrication conditions. The results from the measured constriction resistance using the hypothesis of a single circular contact was compared with those of Hertzian contact theory and hardness. The resistance correlated well with the asperity contact area and friction when the ball slides on the flat disk spreaded with lubricant film. Therefore, the constriction resistance method was useful to identify the lubrication regimes with respect to various loads and speeds. The results of this work will aid in better prediction of lubrication regimes with respect to the operating conditions.

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