• Title/Summary/Keyword: durable resistance

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A Study on the Strength Properties of Concrete Containing Meta-Kaolin (메타카올린을 사용한 콘크리트의 강도특성에 관한 연구)

  • 김진만;이상수;김동석
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.47-52
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    • 2003
  • This study was performed to investigate the flow behavior of fresh concrete. strength properties, and durability properties on the chloride penetration resistance of hardened concrete containing Meta-Kaolin(MK) in the range from common strength to high strength to facilitate the use. The results are compared with properties of concrete containing Si1ca Fume(SF). As a result. superplasticizer required in MK concrete was decreased by 8-28% compared to SF concrete with the same slump, but MK concrete became more sticky than SF concrete. It was also found that considering the strength, the optimal cement replacement ratio of MK was 15%, and MK had concrete durable and dense by decreasing the average pore diameter of concrete.

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The Roles of Aramid Pulp and Potassium Titanate Whisker in the Automotive Friction Materials (자동차용 마찰재에 사용되는 아라미드 섬유와 티탄산칼륨 섬유의 역할)

  • Kim, Seong-Jin;Lim, Hyun-Woo;Jang, Ho
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1999.11a
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    • pp.213-218
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    • 1999
  • Friction and wear characteristics of novolac resin-based friction materials reinforced with aramid pulp and potassium titanate were investigated by using a pad-on-disk type friction tester. Friction properties such as friction stability, surface morphology, and wear rate varied according to the relative amount of aramid pulp and potassium titanate. The friction materials reinforced with both aramid pulp and potassium titanate showed superior friction stability and wear resistance due to the formation of durable transfer layer.

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Synthesis of Blue Acid Dyes having Antimicrobial Property and its Application on Nylon Fiber (설파제를 이용한 청색 항균 산성염료의 합성 및 나일론 소재에 대한 적용)

  • Hong, Jin-Pyo;Yoon, Seok-Han;Kim, Mi-Kyung;Son, Song-I
    • Textile Coloration and Finishing
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    • v.20 no.1
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    • pp.22-27
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    • 2008
  • Sulfadiazine and silver sulfadiazine are well-known bactericidal agent routinely used clinical settings. Antimicrobial acid dyes were synthesized by introducing sulfadiazine or silver sulfadiazine and applied on nylon fabric. The Chemical Structure of the Synthesized dyes was identified by HPLC-mass. The dyeability of synthesized acid dyes for nylon fabric was similar to commercial acid dyes. Resistance to washing, rubbing and lightfastness were good. Nylon fabrics dyed with synthesized acid dyes had good antimicrobial properties. Durable antimicrobial properties after 20 times washing have shown good result that reduction ratio of colonies, is 99.9 %. Mixed dyeing were carried out using commercial acid dyes(leveling type) and synthesized dyes. The mixed dyeings have also shown good antimicrobial properties.

Performance of a Ceramic Fiber Reinforced Polymer Membrane as Electrolyte in Direct Methanol Fuel Cell

  • Nair, Balagopal N.;Yoshikawa, Daishi;Taguchi, Hisatomi
    • Membrane Journal
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    • v.14 no.1
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    • pp.53-56
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    • 2004
  • Direct Methanol Fuel Cell (DMFC) is considered as a candidate technology for applications in stationary, transportation as well as electronic power generation purposes. To develop a high performance direct methanol fuel cell(DMFC), a competent electrolyte membrane is needed. The electrolyte membrane should be durable and methanol crossover must be low. One of the approaches to increase the stability of generally used polymer electrolyte membranes such as Nafion against swelling or thermal degradation is to bond it with an inorganic material physically or chemically. In Noritake Company, we have developed a novel method of reinforcing the polymer electrolyte matrix with inorganic fibers. Methanol crossover values measured were significantly lower than the original polymer electrolyte membranes. These fiber reinforced electrolyte membranes (FREM) were used for DMFC study and stable power output values as high 160 mW/$\textrm{cm}^2$ were measured. The details of the characteristics of the membranes as well as I-V data of fuel cell stacks are detailed in the paper.

An Experimental Study on the Performance of Wire Mesh Reinforced Porous Concrete (Wire Mesh보강 포러스콘크리트의 성능평가에 관한 실험적 연구)

  • 권혁준;이택우;김선용;박승범
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10b
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    • pp.1227-1232
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    • 2000
  • In this study the mechanical properties of various wire mesh reinforcing porous concrete mixtures are investigated. A properly designed porous concrete pavements provides a durable riding surface. It also eliminates puddles and standing water, resulting in improved skid resistance. The most popular application is that of light-traffic volume roadways such as parking lots, resident roads, driveways, and sidewalks. Flexural strength and toughness index are examined for wire mesh reinforcing porous concrete. Type of Wire mesh is divided into three cases, A type, B type and C type. It shows A type is most excellent shape of destruction of slab specimen is similar to that of flexural specimen. The aim of this paper is to present the results of a pilot study undertaken to examine the extent to which wire mesh reinforced porous concrete can be used as a continuous paving materials.

Corrosion Protection Systems on Reinforcement Steep in Marine Concrete Structures (해양콘크리트 구조물의 철근방식 기법에 관한 실험연구)

  • 한기훈;장지원;이강균;정영수
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.04a
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    • pp.265-271
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    • 1997
  • Marine concrete structures have been exposed to salt from ocean environments. Chloride-penetration into marine concrete structures should accelerate the corrosion of reinforcement steel, which may severely affect the durability of them. Major concerns are to develop durable concrete for high corrosion resistance of reinforcing steel embedded in concrete. The objective of this experimental study is to investigate adequate usage of corrosion inhibitors by evaluating corrosion level in 80 specimen located in the labatory and in the site. 80 specimen of cube 20${\times}$20${\times}$11.5 and 63 specimen of slab 30${\times}$30${\times}$10 are made for this study.

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An experimental Study for the Maximun Curing Temperature Effect on the Freezing and Thawing of Steam Curing Concrete (증기양생콘크리트의 최고양생온도변화가 콘크리트의 동결융해저항성에 미치는 영향)

  • Youn, Suk;Choi, Se-Gyu;Kim, Dong-Sin;Yu, Sung-Yong;Kim, Saeng-Bin
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.04a
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    • pp.170-176
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    • 1997
  • The published works on steam curing effect have been generally concentrated on the subject, "compressive strength". However a practical test for durable steam curing concrete products has not been performed in domestic. In this study, the maximum temperature of steam is considered as a major variable to investigate the freezing and thawing resistance of the steam curing concrete. All of the specimen were cured for 24 hours which included presteaming 4 hour. Finally we found that the most effective curing condition is the case of one-day and 14-day specimens after the 24 hours steam curing at $74^{\cire}C$ degree curing temperature. It is also found that the durability of one-day samples are much weaker than those of 14-day samples. Consequently, we can conclude that the samples that produced immediately after a steam curing are more possible to deteriorate from the freezing and thawing environment.vironment.

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Development of High Performance Concrete Tunnel Linnig with Large Dimension (대단면 터널용 고성능 콘크리트 라이닝의 개발)

  • Cha Hun;Lee Chang Hoon;Sohn Yu Shin;Yoon Young Soo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05b
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    • pp.53-56
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    • 2005
  • High flowable concrete was first developed in 1988 to achieve durable concrete structures. High flowable concrete can improve workability sharply reason why the concrete has properties of resistance to segregation, filling ability, passing ability without compacting. Therefore, as we apply a high flowable concrete to a large dimensional tunnel which constructed in special environment, we can get workability, strength and durability required. Tunnel lining concrete with a large dimension has to use necessarily fly ash and slag for the properties of high flowability and watertight. We can expect improvement of workability and durability, mitigation of hydration, reducing shrinkage, enhancement of watertight by using cementitious materials. This paper proposes investigations for establishing a mix-design method and high flowability-strength testing methods have been carried out from the viewpoint of making a standard concrete tunnel lining with large dimension a standard.

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Charge/Discharge Characteristics of Lithium ion Secondary Battery Using Ag-deposited Graphite as Anode Active Material (은 담지한 흑연을 부극 활물질로 이용한 Lithium ion 2차전지의 충방전 특성)

  • 김상필;조정수;박정후;윤문수
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.9
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    • pp.727-732
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    • 1998
  • Ag-deposited graphite powder was prepared by a chemical reduction method of metal particles onto graphite powder. X-ray diffraction observation of Ag-deposited graphite powder revealed that silver existed in a metallic state, but not in an oxidized one. From SEM measurement, ultrafine silver particles were highly dispersed on the surface of graphite particles. Cylindrical lithium ion secondary battery was manufactured using Ag-deposited graphite anodes and $LiCoO_2$ cathodes. The cycleability of lithium ion secondary battery using Ag-deposited graphite anodes was superior to that of original graphite powder. The improved cycleability may be due to both the reduction of electric resistance between electrodes and the highly durable Ag-graphite anode.

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Tumor bioenergetics: An emerging avenue for cancer metabolism targeted therapy

  • Kee, Hyun Jung;Cheong, Jae-Ho
    • BMB Reports
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    • v.47 no.3
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    • pp.158-166
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    • 2014
  • Cell proliferation is a delicately regulated process that couples growth signals and metabolic demands to produce daughter cells. Interestingly, the proliferation of tumor cells immensely depends on glycolysis, the Warburg effect, to ensure a sufficient amount of metabolic flux and bioenergetics for macromolecule synthesis and cell division. This unique metabolic derangement would provide an opportunity for developing cancer therapeutic strategy, particularly when other diverse anti-cancer treatments have been proved ineffective in achieving durable response, largely due to the emergence of resistance. Recent advances in deeper understanding of cancer metabolism usher in new horizons of the next generation strategy for cancer therapy. Here, we discuss the focused review of cancer energy metabolism, and the therapeutic exploitation of glycolysis and OXPHOS as a novel anti-cancer strategy, with particular emphasis on the promise of this approach, among other cancer metabolism targeted therapies that reveal unexpected complexity and context-dependent metabolic adaptability, complicating the development of effective strategies.