• 제목/요약/키워드: LHC

검색결과 59건 처리시간 0.023초

시멘트 종류에 따른 저발열 콘크리트의 품질특성에 관한 연구 (A Study on the Quality Properties of Low Heat Concrete according to Kinds of Cement)

  • 김성;최성우;조현태;전준영;류득현
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2006년도 추계 학술발표회 논문집
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    • pp.777-780
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    • 2006
  • Recently, owing to the development of industry and the improvement of building techniques, the concrete structure is becoming larger and higher. In hardening these large concrete, the heat of hydration gives rise to considerable thermal stress depending on the size and environmental condition of concrete, which might cause thermal cracking. Especially, the crack may cause severe damage to the safety and the durability of concrete structure. This study is investigated the thermal properties of concrete according to several binder conditions, such as OPC, Belite Rich Cement(BRC), Low-Heat-Mixed Cement(LHC), Fly ash added cement. As a result of this study, the Flowability of concrete was beetter with BRC and LHC than FA(25) and OPC. On the other hand, LHC gets superior effect in the control of heat hydration, it's caused by the volume of OPC.

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탄소나노튜브 및 카본블랙 강화 고무복합재료의 변형에 의한 결정화가 기계적 특성에 미치는 영향 (Effects of Strain-Induced Crystallization on Mechanical Properties of Elastomeric Composites Containing Carbon Nanotubes and Carbon Black)

  • 성종환;류상렬;이동주
    • 대한기계학회논문집A
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    • 제35권9호
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    • pp.999-1005
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    • 2011
  • 고무복합재료에 대해 변형에 의한 결정화(SIC)가 기계적 특성에 미치는 영향을 연신율(${\lambda}$) 및 다중벽 탄소나노튜브(CNT)와 카본블랙(CB)의 함유량을 함수로 하여 연구하였다. 시차 주사 열량(DSC) 분석을 통해 CB 및 CNT의 함유량에 따라 결정화 정도가 증가함을 확인 하였다. 또한 연신율이 증가함에 따라 복합재료의 유리전이온도(Tg)는 증가하였고, 결정화 잠열 값(LHc)은 ${\lambda}$=1.5에서 최대값을 보였다. CNT의 함유량 증가에 따라 기계적 특성과 LHc는 비례관계임을 확인하였다. 열 중량 분석(TGA)을 통해 기지의 소실율은 94.3%였고, 복합재료의 소실율은 보강재의 함유량 증가에 따라 감소하였다. 인장탄성율 비는 고무 내의 CNT 배향으로 인장강도 비보다 높게 나타났다.

A Disk-based Archival Storage System Using the EOS Erasure Coding Implementation for the ALICE Experiment at the CERN LHC

  • Ahn, Sang Un;Betev, Latchezar;Bonfillou, Eric;Han, Heejune;Kim, Jeongheon;Lee, Seung Hee;Panzer-Steindel, Bernd;Peters, Andreas-Joachim;Yoon, Heejun
    • Journal of Information Science Theory and Practice
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    • 제10권spc호
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    • pp.56-65
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    • 2022
  • Korea Institute of Science and Technology Information (KISTI) is a Worldwide LHC Computing Grid (WLCG) Tier-1 center mandated to preserve raw data produced from A Large Ion Collider Experiment (ALICE) experiment using the world's largest particle accelerator, the Large Hadron Collider (LHC) at European Organization for Nuclear Research (CERN). Physical medium used widely for long-term data preservation is tape, thanks to its reliability and least price per capacity compared to other media such as optical disk, hard disk, and solid-state disk. However, decreasing numbers of manufacturers for both tape drives and cartridges, and patent disputes among them escalated risk of market. As alternative to tape-based data preservation strategy, we proposed disk-only erasure-coded archival storage system, Custodial Disk Storage (CDS), powered by Exascale Open Storage (EOS), an open-source storage management software developed by CERN. CDS system consists of 18 high density Just-Bunch-Of-Disks (JBOD) enclosures attached to 9 servers through 12 Gbps Serial Attached SCSI (SAS) Host Bus Adapter (HBA) interfaces via multiple paths for redundancy and multiplexing. For data protection, we introduced Reed-Solomon (RS) (16, 4) Erasure Coding (EC) layout, where the number of data and parity blocks are 12 and 4 respectively, which gives the annual data loss probability equivalent to 5×10-14. In this paper, we discuss CDS system design based on JBOD products, performance limitations, and data protection strategy accommodating EOS EC implementation. We present CDS operations for ALICE experiment and long-term power consumption measurement.

REPRESSION OF Lhcb GENES FOR CHLOROPHYLL a/b-BINDING PROTEINS UNDER HIGH-LIGHT CONDITIONS IN Chlamydomonas

  • Haruhiko Teramoto;Akira Nakamori;Jun Minagawa;Ono, Taka-aki
    • Journal of Photoscience
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    • 제9권2호
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    • pp.373-375
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    • 2002
  • Lhcb genes encoding light-harvesting chlorophyll-a/b binding (LHC) proteins of photosystem (PS) II were comprehensively characterized using the expressed sequence tag (EST) databases in the green alga, Chlamydomonas reinhardtii. The gene family was composed of eight Lhcb genes including four new genes, which were isolated and sequenced. The effects of light intensity on the levels of mRNAs accumulation of multiple Lhcb genes were studied under various conditions. The results indicate that Lhcb genes are coordinately regulated in response to light conditions, and repressed when the input light energy exceeded the requirement for $CO_2$ assimilation. The effects of high light on the expression of the Lhcb genes observed in the presence of an electron transport inhibitor, DCMU, and in mutants deficient in photosynthetic reaction centers suggest the presence of two alternative mechanisms for regulating the genes expression under high-light conditions.

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An Empirical Analysis of Worldwide Cyberinfrastructure

  • Cho, Manhyung
    • Asian Journal of Innovation and Policy
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    • 제4권3호
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    • pp.381-396
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    • 2015
  • Cyberinfrastructure is a research infrastructure that provides an environment in which research communities can get access to distributed resources and collaborate at unprecedented levels of computation, storage, and network capacity. The Worldwide LHC Computing Grid (WLCG) is a global collaborative project of computing or data centers that enables access to scientific data generated by the Large Hadron Collider (LHC) experiments at CERN. This case study analyzes the WLCG as a model of cyberinfrastructure in research collaboration. WLCG provides a useful case of how cyberinfrastructure can work in providing an infrastructure for collaborative researches under data-intensive paradigm. Cyberinfrastructure plays the critical role of facilitating collaboration of diverse and widely separated communities of researchers. Data-intensive science requires new strategies for research support and significant development of cyberinfrastructure. The sustainability of WLCG depends on the resources of partner organizations and virtual organizations at international levels, essential for research collaboration.

Chloride binding isotherms of various cements basing on binding capacity of hydrates

  • Tran, Van Mien;Nawa, Toyoharu;Stitmannaithum, Boonchai
    • Computers and Concrete
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    • 제13권6호
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    • pp.695-707
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    • 2014
  • This study investigated the chloride binding isotherms of various cement types, especially the contributions of C-S-H and AFm hydrates to the chloride binding isotherms were determined. Ordinary Portland cement (OPC), Modified cement (MC), Rapid-hardening Portland cement (RHC) and Low-heat Portland cement (LHC) were used. The total chloride contents and free chloride contents were analyzed by ASTM. The contents of C-S-H, AFm hydrates and Friedel's salt were determined by X-ray diffraction Rietveld (XRD Rietveld) analysis. The results showed that OPC had the highest chloride binding capacity, and, LHC had the lowest binding capacity of chloride ions. MC and RHC had very similar capacities to bind chloride ions. Experimental equations which distinguish the chemically bound chloride and physically bound chloride were formulated to determine amounts of the bound chloride basing on chloride binding capacity of hydrates.