• Title/Summary/Keyword: 균일 강도

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Control of histamine-forming bacteria by probiotic lactic acid bacteria isolated from fish intestine (생선 내장으로부터 분리된 프로바이오틱 유산균에 의한 히스타민 생산균의 제어)

  • Lim, Eun-Seo;Lee, Nahm-Gull
    • Korean Journal of Microbiology
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    • v.52 no.3
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    • pp.352-364
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    • 2016
  • In this study, we examined in vitro the potential probiotic properties of lactic acid bacteria (LAB) obtained from the fish intestine and their ability to degrade histamine through the production of diamine oxidase (DAO) enzymes and bacteriocin. Among 97 LAB strains isolated from the intestine of croaker, flatfish, pollack, and rockfish, CIL08, CIL16, FIL20, FIL31, PIL45, PIL49, PIL52, and RIL60 isolates exhibited excellent survival rates under simulated gastrointestinal tract conditions, high adhesion ability to HT-29 epithelial cells, and resistance to the antibiotics such as amoxicillin, ampicillin, erythromycin, penicillin G, streptomycin, tetracycline, or vancomycin. In addition, these strains did not produce histamine in decarboxylating broth containing histidine. In particular, 4 strains (CIL08, FIL20, PIL52, and RIL60) that may produce DAO were significantly able to degrade histamine. The bacteriocins produced by FIL20, FIL31, and PIL52 LAB inhibited the growth and histamine production of Enterococcus aerogenes CIH05, Serratia marcescens CIH09, Enterococcus faecalis FIH11, Pediococcus halophilus FIH15, Lactobacillus sakei PIH16, Enterococcus faecium PIH19, Leuconostoc mesenteroides RIH25, or Aeromonas hydrophilia RIH28. Histamine-producing strains isolated from fish intestine were found to reduce histamine accumulation during co-culture with CIL08, FIL20, PIL52, and RIL60 LAB showing histamine degradation or bacteriocin production ability. The probiotic strains preventing histamine formation were identified as Pediococcus pentosaceus CIL08, Lactobacillus plantarum FIL20, Lactobacillus paracasei FIL31, Lactobacillus sakei PIL52, and Leuconostoc mesenteroides RIL60 with high similarity based on 16S rRNA gene sequencing.

Tensile Strength and Surface Characteristics of Mn Steel with Ti Addition (Ti을 첨가한 Mn 강의 인장특성과 표면특성)

  • Ryung-kyung Hwang;Sung-Tae Yoon;Gyun-Yung Lee;Sun-Joong Hwang
    • Journal of Korea Foundry Society
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    • v.44 no.1
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    • pp.9-15
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    • 2024
  • In this study, in order to improve the lifespan of parts made of manganese steel, manganese steel was cast by varying the amount of Ti added to the steel. In order to confirm the characteristics of the cast material, processing characteristics including tensile and surface characteristics and bearing ratio were investigated. It was confirmed that when the amount of Ti added to high manganese steel exceeds 0.5%, the strength of the alloy is improved due to grain refinement, and fine carbides are formed inside the steel. This results in increased resistance to surface wear compared to the alloy with only Mn added. There was no significant difference in the increase in tensile strength as the Ti content in manganese steel was increased. However, inclusion of Ti showed a small but greater effect on wear resistance compared to Mn, and the size and the distribution of carbides become coarse depending on the Ti content. and was evenly distributed. It was confirmed that the strength and surface properties of manganese steel can be improved by the addition of Ti to improve the lifespan of parts made with this steel. It was found that Ti is effective in developing materials with excellent wear resistance due to refinement of dendrite crystal grains. In the samples where Ti was added, the carbide appears to increase the resistance to surface roughness, and due to the nature of Mn steel, surface hardening begins to occur, which appears to extend the life.

The Investigation of Stress Block of C-Shaped Specimen for High-Strength Polymer Concrete (고강도 폴리머 콘크리트 C 형보의 응력블럭 고찰)

  • 김관호;연규석;김남길;박광수;신수균;이준구
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.1023-1028
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    • 2001
  • This study was conducted to develop a procedural method to produce a high strength polymer concrete using polyester resin to experimentally examine the stress block properties of the high strength polymer concrete. C-shaped specimens were Produced and test to compute parameter of the stress block. They were $k_{1}$ : 0.73 and $\gamma$ : 0.845, respectively. $k_{1}$ is the ratio of the depth of the maximum compressive strength of the beam

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UCC 게시와 시청의 동기(Motivation)에 관한 연구

  • Gang, Yu-Ri;Nam, Hyeong-Gyun;Park, Cheol
    • 한국경영정보학회:학술대회논문집
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    • 2007.06a
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    • pp.67-72
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    • 2007
  • 본 연구는 최근 이슈가 되고 있는 UCC를 네티즌들이 올리는 동기와 내려보는 동기를 분석하였다. UCC생산자와 소비자의 동기를 파악하면 UCC서비스 사이트의 마케팅 전략과 UCC를 마케팅에 활용하고자 하는 기업들에게 시사점을 줄 수 있을 것이다. UCC를 시청하고 게시하는 동기에는 각각 사회적인 측면, 개인적인 측면, 정보추구 측면, 오락적인 측면, 경제적인 측면 등 이상 다섯 가지 동기로 분류되었고 이들의 특성에 대해 분석해 봄으로써 이런 동기가 UCC마케팅 전략에 어떻게 적용될 수 있는지 제시하였다.

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Spray Performance Evaluation of Knapsack Type Sprayer (배부식 방제기의 분무 성능평가)

  • 김영주;곽현환;강태경;이중용
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 2003.02a
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    • pp.257-263
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    • 2003
  • 방제는 재배작물에 발생하는 병충해를 최소화하여 농산물의 품질을 향상시키고 생산성을 증대시키는 중요한 관리 작업이며, 작물을 재배하는 동안에 여러 번 작업해야하며 노동 강도가 크고 농약중독 위험 때문에 농민이 기피하는 작업이다. 방제 방법에는 화학적 방제와 생물학적 방제, 농업적 방제, 기계적 방제 등 여러 방법이 있다. 화학적 방제는 잡초나 해충, 균의 밀도가 경제적 피해 수준 이하에서 유지되면서 더욱 확산되지 않도록 천연 또는 인공 화학물질을 이용하여 병해충이나 잡초를 억제는 방제방법으로 현재는 물론 가까운 미래에도 주를 이룰 것으로 예상된다. (중략)

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Study on Strength Development of Concrete for Top-Down Method (역타공법에 적용을 위한 콘크리트 강도성상 연구)

  • 정근호;이종균;김영회;이영도;정상진
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10c
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    • pp.48-53
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    • 1998
  • The purpose of this study to fine the mixture of concrete for Top-Down method. As a result, In fresh concrete, slump value and slump-flow value were increased as fly ash concrete(10% ratio). When plasticizer was added 1.5% by weigh of binder in concrete, no fly ash concrete and fly ash concrete(10% ratio) all occurred segregation. And, no fly ash concrete and fly concrete(10% ratio) all showed compressive strength development close plain concrete as increasing plasticizer quantity. Especially, in case of 1.5% plasticizer of binder showed high compressive strength development.

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Cracking Control of Concrete Deck in Steel-Concrete Composite Bridges (강합성 교량의 바닥판 콘크리트 균열관리)

  • 박해균;이명섭;안병제;곽효경;서영재
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.355-362
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    • 2001
  • This study deals with cracking control of concrete deck in steel-concrete composite bridges according to the concrete slab casting sequences. In correlation studies between casting sequences, time dependent effects of concrete creep and shrinkage are implemented in the analytical model. Finally, the methods of cracking control in terms of concrete slump and relative humidity are suggested to prevent early transverse cracking of concrete slab.

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Analysis of Switching Overvoltage on Operating Reclosing in Combined Transmission Systems (혼합송전계통에서 재폐로 시행시 개폐과전압 해석)

  • Lim, Kwang-Sik;Lee, Jong-Boem;Jung, Chae-Kyun;Kang, Ji-Won;Park, Hung-Sok
    • Proceedings of the KIEE Conference
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    • 2008.11a
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    • pp.391-393
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    • 2008
  • This paper is analysed by switching overvoltage on operating reclosing in 154 [kV] combined transmission systems. Combined transmission systems are modeled by EMTP/ATPDraw program. It is fault condition that simulate high resistance earth fault. The simulation is carried out considering variation of parameters such as resistance value of fault point and rate of underground line.

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