• 제목/요약/키워드: Environmental durability

검색결과 835건 처리시간 0.026초

Glutaraldehyde를 이용한 설파제의 합성과 지속성에 관한 연구 (A Study on the Durability and Synthesis of Sulfa Agents Using Glutaraldehyde)

  • 윤철훈
    • 한국환경보건학회지
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    • 제30권5호
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    • pp.374-377
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    • 2004
  • Dual actions are the most recently used delivery system in drug study. Dual-action agents are unique chemical entities comprised of two different type of antibacterial compounds covalently linked together in a single molecule in such a way that both components are able to exert their bactericidal properties. Crosslinked sulfadiazine-sulfanilamide such as antibiotics is synthesized by synthetic handle with glutaraldehyde. As a result, New synthetic antibacterial agent exhibited the broad antibacterial activities against Gram(+) and Gram(-) of 4 strains and a long durability supposing that the stomach and blood.

사이버교육에서 만족도와 성취도에 대한 심리적 사회적요인에 관한 연구 (The Influences of Psychological and social factors toward Academic Satisfaction and Achievement in Cyber Education)

  • 김경우
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2015년도 제51차 동계학술대회논문집 23권1호
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    • pp.111-113
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    • 2015
  • This paper investigate the empirical implications. They were to verify the influences of psychological and environmental factors toward performance satisfaction and durability. The results show that actional environment on academic satisfaction in learning is the most important factor. The effect of academic satisfaction on learning durability proved to be statistically significant. The results suggest that actional environment should be considered with top priority to increase the academic satisfaction. Learning satisfaction, academic vision, and academic satisfaction to enhance students' intention to continue studies are important.

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지속가능한 제품재설계를 위한 신뢰성기법의 적용방법 (Application of Reliability Technology for Sustainable Product Redesign)

  • 이종범;정원
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제9권4호
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    • pp.343-349
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    • 2009
  • One of the recent hot issues in the manufacturing business is how to incorporate environmental attributes into product and process design. Design for environment considers the potential environmental impact of a product throughout its life-cycle. In the case of something breaks, it can become waste immediately, hence reliability and durability is the essential part of product design. This paper presents reliability technology for sustainable product design to improve the product longevity that extends performance life, serviceability and durability. The presented method will help to develop a sound design and avoid weak links to minimize the waste.

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주방위생에서 항균수세미의 효과 (Inhibition Effect of Germ-resistant Sponge on Microbial Growth in Kitchen Hygiene)

  • 이용욱;나승식;조성범;정지연;박성기
    • 한국환경보건학회지
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    • 제22권4호
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    • pp.109-121
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    • 1996
  • It was intended to investigate the effect of the microbiological kitchen hygiene such as dishclothes and scrubbers. The 8indicator organisms (standard plate counts, coliform, heterotroph, enterococcus, staphylococcus, heat-stable bacteria, psychrotroph, Pseudomonas aeruginosa) were detected highly in dishwaters, dishcloth and scrubber. Coliform and Staphylococcus aureus were appeared on dishcloth dominantly than the scrubber, and the scrubbers were intruded by hetrotrophs and psychrotrophs numerously than dishclothes. The germ-resistant sponge inhibited the growth of the most of test strain, and appeared the about 100% reduction rate after 24 hr, but did not affect Pseudomonas aeruginosa and P. fragi so typically after 24 hr. The anti-microorganism durability of germ-resistant sponge, treated with food soil, was maintained by 10 days, the early stage strain density was founded in 20 days, and the strains grew after 30 days.

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강합성 콘크리트 복공판의 내력시험에 관한 연구 (A Study on the Bearing Capacity of Steel Composite Concrete Lining Board)

  • 백신원;김용곤
    • 한국안전학회지
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    • 제27권6호
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    • pp.122-126
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    • 2012
  • Steel lining board usually is used as a floor on the temporary steel bridges. It also is installed in the subway construction site. However, in particular in subway construction, renovations and site of old bridges, these steel lining board structures have a problem such as noise, accidents and slip hazards. So steel composite lining board is being developed to solve this problem. Steel composite lining board consists of compressive concrete showing excellent performance in slip, durability, resistance and noise, lower tensile and shear steel showing high safety, effective and superior workability in many respects. Steel composite lining board structure gradually is used in many construction sites, because it has a high quality such as durability, little noise and slip. In this study, flexural tests of steel composite lining board in accordance with welding patterns were conducted to compare the performance of the structure.

REACTIVITY AND DURABILITY OF V2O5 CATALYSTS SUPPORTED ON SULFATED TIO2 FOR SELECTIVE REDUCTION OF NO BY NH3

  • Choo, Soo-Tae;Nam, Chang-Mo
    • Environmental Engineering Research
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    • 제10권1호
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    • pp.31-37
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    • 2005
  • The selective catalytic experiments using both sulfated/sulfur-free titania and V2O5/TiO2 catalysts have been conducted for NO reduction by NH3 in a packed-bed, down-flow reactor. The sulfated and vanadia loaded titania exhibited higher activity for NO removal than the sulfur-free catalysts, where > 90% NO removal was achieved over the sulfated V2O5/TiO2 catalyst between 280∼500 C. The surface structure of vanadia species on the catalyst surface played a critical role in the high performance of catalysts in which the existence of monomeric/polymeric vanadate is revealed by Raman spectra studies. Water vapor and SO2 were added to the reacting system for the catalyst deactivation tests. At higher temperatures (T ≥ 350 C), little deactivation was observed over the sulfated V2O5/TiO2 catalysts, showing good durability against SO2 and water vapor, which is compared with deactivation at lower temperatures.

친환경형 중온 폴리머 개질 아스팔트 바인더의 상대적 물성 비교평가 (Relative Property Evaluation of Pro-Environmental Warm Polymer-Modified Asphalt Binder)

  • 김낙석;이진구
    • 한국재난정보학회 논문집
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    • 제6권1호
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    • pp.10-24
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    • 2010
  • In this paper, warm asphalt binder was proposed as a substitute for the polymer-modified asphalt binder to get higher viscosity than that of the polymer-modified at the same temperature. Performance grade test and rotational viscosity of warm asphalt binder were conducted to evaluate the property variations due to the addition of admixture. Research results showed that the viscosity of warm asphalt binder at $100^{\circ}C$ was similar to that of the conventional asphalt binder. The performance and durability of warm asphalt binder were also comparable to those of the polymer-modified. It is considered that the active applications of warm asphalt binder can reduce environmental damages due to less diffusions of carbon dioxide compared to the conventional.

콘크리트 복개구조물용 보수재료의 성능 평가 (Evaluation of Performance on Repair Materials for Creek Concrete Structures)

  • 이창수
    • 한국구조물진단유지관리공학회 논문집
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    • 제6권1호
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    • pp.205-212
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    • 2002
  • The deterioration rate of concrete structures in urban area is accelerated due to rapid urbanization and environmental pollution. Repair materials and methods newly introduced in Korea should be investigated whether they are appropriate for the urban environment in Korea. The creek concrete structures are exposed in severe environmental condition than others. Based on these background in mind, the study is focused on evaluation of performance on repair materials used to rehabilitate creek concrete structures. To evaluate the performance of repair materials, four kinds of repair materials were selected based on polymer emulsion. This experimental study was conducted on fundamental performance such as setting time, compressive strength, bending strength, bonding strength, thermal expansion coefficient, and durability performance such as chloride diffusion, carbonation, chemical attack, and steel corrosion rate. On the basis of this study, the optimal repair material which is proper to the environment condition can be selected and service life of creek concrete structures can be extended. As a result, the life cycle cost can be reduced and the waste of material resources will be cut down.

수팽창 지수재의 방수 성능 및 내구성 평가 (Evaluation of waterproof and durability of hydrophilic waterstop)

  • 최우용;이현필;전기찬;이석원
    • 한국터널지하공간학회 논문집
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    • 제16권2호
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    • pp.117-124
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    • 2014
  • 최근 국내에서는 쉴드 TBM (Tunnel Boring Machine)을 이용한 터널 굴착에 대한 관심이 크게 증가하고 있다. 쉴드 TBM 터널은 비배수 터널로써 세그먼트 이음부에서 누수가 발생할 경우에는 터널의 사용성 및 안정성에 문제가 될 수 있다. 본 연구에서는 첫째로 쉴드 TBM 터널의 세그먼트 시공 시 시공오차 및 세그먼트 과다변형에 의한 수팽창 지수재의 방수 성능 변화를 알아보았고, 두 번째로 지하수와 해수에 있을 수 있는 황산염과 염화물에 의한 수팽창 지수재의 내구성 저하를 알아보았다. 시험결과, 체결각 불합치가 $2^{\circ}$이상으로 시공 오차가 발생한 경우에는 수팽창 지수재의 차수 능력을 기대하기는 어려운 것으로 판단된다. 또한 수팽창 지수재가 황산마그네슘 용액에 장시간 노출될 경우에는 지수재의 내구 성능에 문제가 있을 수 있을 것으로 판단된다.

가속내구성 조건에 따른 건축용 유기계 단열재의 단열성능 변화 (Changes in Insulation Performance of Organic Insulating Materials for Building Construction by Accelerated Durability Test Conditions)

  • 임순현;이건철
    • 한국건축시공학회지
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    • 제16권6호
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    • pp.595-601
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    • 2016
  • 현재 건축구조물에 사용되는 단열재의 단열성능은 초기성능을 기준으로 설계 시에만 반영하고 있으며, 장기 내구성 저하에 따른 단열성능 감소는 반영되고 있지 않다. 본 연구에서는 가속내구성 시험을 통해 단열재의 내구성 저하에 따른 단열성능 저하를 검토하였다. 연구결과, 발포폴리스티렌 단열재 비드법의 경우 표준환경 조건 및 실험실 가속 시험 조건에서는 경시변화에 따른 성능저하가 나타나지 않았으나, 동결 융해 시험 조건에는 성능이 저하하는 것으로 나타났다. 반면, 압출법의 경우 동결 융해 시험 조건에서는 단열성능 저하가 작았지만, 경시변화 초기에 내부 가스의 방출로 급격한 성능저하를 나타내었다. 또한, 경질 폴리우레탄 폼 단열재의 경우 다른 단열재에 비해 초기 단열성능이 매우 뛰어났으나, 실험실 가속 시험조건 및 동결 융해 시험 조건에서는 성능이 다소 저하하는 것으로 나타났다.