• Title/Summary/Keyword: release property

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Evaluation of Models for Estimating Shrinkage Stress in Patch Repair System

  • Kristiawan, Stefanus A.
    • International Journal of Concrete Structures and Materials
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    • v.6 no.4
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    • pp.221-230
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    • 2012
  • Cracking of repair material due to restraint of shrinkage could hinder the intended extension of serviceability of repaired concrete structure. The availability of model to predict shrinkage stress under restraint condition will be useful to assess whether repair material with particular deformation properties is resistance to cracking or not. The accuracy in the prediction will depend upon reliability of the model, input parameters, testing methods used to characterize the input parameters, etc. This paper reviews a variety of models to predict shrinkage stress in patch repair system. Effect of creep and composite action to release shrinkage stress in the patch repair system are quantified and discussed. Accuracy of the models is examined by comparing predicted and measured shrinkage stress. Simplified model to estimate shrinkage stress is proposed which requires only shrinkage property of repair material as an input parameter.

Effects of Composts and Soil Amendments on Physicochemical Properties of Soils in Relation to Phytophthora Root and Crown Rot of Bell Pepper

  • Kim, Ki-Deok;Nemec, Stan;Musson, George
    • The Plant Pathology Journal
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    • v.16 no.5
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    • pp.283-285
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    • 2000
  • Two field tests were conducted in 1995 to examine the effects of composts and soil amendments on physicochemical properties of soil in relation to Phytophthora root and crown rot of bell pepper. Chitosan, crab shell waste, humate, sewage sludge-yard trimmings, and wood chips were applied to test plots, some of which affected the levels of P, K, Mg, pH, and H. Physicochemical properties were not related with disease incidence, but percent organic matter, estimated nitrogen release, K, and Mg were correlated with total microbial activity. The elements K and Mg were especially responsible for the increased soil microbial activity that could affect development of root and crown rot of pepper.

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A Numerical Study on Natural Convection in A Three-Phase GIS Busbar (3상 GIS Busbar내 자연대류에 대한 수치해석적 연구)

  • Wang, Yangyang;Hahn, Sung-Chin;Kim, Joong-Kyoung;Kang, Sang-Mo
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.107-108
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    • 2008
  • The temperature rise of GIS (Gas Insulated Switchgear) busbar system is a vital factor that affects its performance. In this paper, a two-dimensional model is presented by commercial code CFX11 for the evaluation of natural convection in the busbar system. In the model, SF6 (Sulfur Hexafluoride) is used to insulate the high voltage device and improves the heat transfer rate. The power losses of a busbar calculated by the magnetic field analysis are used as the input data to predict the temperature rise by the nature convection analysis. The heat-transfer coefficients on the boundaries are analytically calculated by applying the Nusselt number considering material property and model geometry for the natural convection. The temperatures of the tank and conductors from CFX simulation and the experiment were compared. The results show a good agreement. In the future, we will calculate the 3-D model and try to reduce the temperature by adjusting some dimensional parameters.

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Bioavailability Study on Design of Preparations (제제설계(製劑設計)에서의 생체내(生體內) 이용솔(利用率)에 관(關)한 연구(硏究))

  • Lee, Chul-Woo
    • Journal of Pharmaceutical Investigation
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    • v.5 no.4
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    • pp.7-16
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    • 1975
  • The drug release property from the coated tablets which contain 291mg of acetylsalicylic acid were estimated from comparison of the blood level and the urinary excretions after oral ingestion of coated tablets and noncoated tablet in human. The coating materials are 2-methyl-5-vinylpyridine-methylacrylic acid copolymer(MPM), dimethyl aminoethyl methacrylate methyl methacrylate copolymer(EE), polyvinyl acetal diethyl aminoacetate(AEA), and shellac. Each of 7 subjects ingested 873mg of acetylsaliylic acid. All tablets are coated approximately $3.5{\pm}0.5%(w/w)$ per tablet with each of the coating materials and met K.P.II. standard for potency and disintegration time. The availability was decreased in the following order:MPM coated tablets>EE coated tablets>AEA coated tablets>> shellac coated tablets.

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Preparation and Characterization of Wheat Germ Agglutinin-conjugated Praecoxin A (Wheat Germ Agglutinin-conjugated Praecoxin A의 제작 및 특성)

  • 김완수;김만석;김범수;이민원;이도익
    • YAKHAK HOEJI
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    • v.45 no.3
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    • pp.302-309
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    • 2001
  • Wheat germ agglutinin (WGA) pectin, which binds to human melanoma cell line, was conjugated with Praecoxin A using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide as a cross-linking agent. Physical mixture (PM) of WGA and Praecoxin A was also prepared by using a non-specific binding property of Praecoxin A to WGA. The WGA:Praecoxin A ratio in the conjugate and PM was approximately 1:18 and 1:20, respectively. The results of hemagglutination assay and enzyme-linked lectin assay indicated that the conjugate and PM maintained the lectin-like properties of the WGA. The binding ratio of conjugate was about 70% during 4-24 hr, but the most of Praecoxin A was released within 24 hr in the case of PM. These results lead to the conclusion that the conjugate is potentially useful for the formulation of injection that requires targeting for melanoma as well as sustained release at the site.

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Synthesis of Sesamol Derivatives and Biological Activities (Sesamol 유도체의 합성 및 생물활성)

  • Cha, Bae-Cheon
    • YAKHAK HOEJI
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    • v.52 no.2
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    • pp.131-136
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    • 2008
  • Sesamol, one of constituents isolated from sesame seed (Sesamum indicum L.) has been known to have natural antioxidant property. Nicotinic acid and clofibric acid have been used for treatment of hyperlipidemia. Sesamol derivatives prepared by conjugation with nicotinic acid (SJ-301) and clofibric acid (SJ-302) were expected to have various biological activity caused by synergistic effect of sesamol. Thus, this study were carried out to investigate the synthesis of sesamol derivatives from seasamol and antihyperlipidemia drugs and their biological activities. As a result, SJ-301 showed a stronger antihyperlipidemia activity in vivo and inhibitory effect on $TNF-{\alpha}$ release in vitro compared to the original agents such as sesamol, nicotinic acid and clofibric acid.

A study on the optical characteristics of selenium thin film (Selenium박막의 광학적 특성연구)

  • 허창수;오영주
    • Electrical & Electronic Materials
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    • v.9 no.1
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    • pp.44-50
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    • 1996
  • In this study, Selenium device was fabricated by vacuum evaporation method with the substrate temperature at room temperature and its electrical and optical properties were investigated to be used in optical device. The film properties largely depended on the transmittance and annealing time, and improved with aging owing to stress release. We found that the photocurrent of the films increase linearly with light illumination. As a result, Selenium device made by this method yielded a short circuit current density of 10.5mA/$\textrm{cm}^2$, an open circuit voltage of 39OmV.

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The Comparative Study of Software Optimal Release Time Based on Log property Distribution (로그형 특성분포에 근거한 소프트웨어 최적 방출시기에 관한 비교 연구)

  • Kim, Hee-Cheul;Park, Hyoung-Keun
    • Proceedings of the KAIS Fall Conference
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    • 2010.05a
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    • pp.149-152
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    • 2010
  • 본 연구에서는 소프트웨어 제품을 개발하여 테스팅을 거친 후 사용자에게 인도하는 시기를 결정하는 방출문제에 대하여 연구되었다. 인도시기에 관한 모형은 무한 고장 수에 의존하는 비동질적인 포아송 과정을 적용하였다. 이러한 포아송 과정은 소프트웨어의 결함을 제거하거나 수정 작업 중에도 새로운 결함이 발생될 가능성을 반영하는 모형이다. 적용모형은 여러 수명 분포들을 적합시키는데 효율적인 특성을 가진 콤페르쯔, 파레토, 로그-로지스틱 모형과 같은 로그형 특성분포를 이용하였다. 따라서 소프트웨어 요구 신뢰도를 만족시키고 소프트웨어 개발 및 유지 총비용을 최소화 시키는 방출시간이 최적 소프트웨어 방출 정책이 된다. 본 논문의 수치적인 예에서는 고장 간격 시간 자료를 적용하고 모수추정 방법은 최우추정법을 이용하여 최적 방출시기를 추정하였다.

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Kinetics of Enriched Chitinase as Extracellular Metabolite in Beauveria bassiana

  • Mondal, Subhoshmita;Datta, Siddhartha;Mukherjee, Alakananda;Bhattacharya, Pinaki
    • Microbiology and Biotechnology Letters
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    • v.47 no.1
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    • pp.96-104
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    • 2019
  • Beauveria bassiana, one of the most common entomopathogenic fungi, has been isolated, pre defined and characterized in-house from soil of tea cultivation area. Experiments have been performed to verify the presence of chitinase as intracellular metabolite and its release as extracellular product rendering the spores with biopesticide activity. Although there are many responsible enzymes for the pest killer action of B. bassiana, binding property of chitinase depending on presence as well as absence of serine supplemented in the media has been studied with respect to the production and kinetics. A programmed investigation conclusively indicates that the isolated spore (hyphae) of B. bassiana has been metabolically enriched with the enzyme chitinase in presence of an externally added amino acid serine with its inhibitory kinetics.

The Status of Damage and Monitoring of Subterranean Termite (Reticulitermes spp.) (Blattodea: Rhinotermitidae) for Wooden Cultural Heritage in Korea (국내 목조문화재에 대한 지중 흰개미 피해 및 모니터링 현황)

  • Im, Ik-Gyun;Cha, Hyun-Seok;Kang, Won-Chul;Lee, Sang-Bin;Han, Gyu-Seong
    • Journal of Conservation Science
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    • v.37 no.3
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    • pp.191-208
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    • 2021
  • In this study, the status of damage by subterranean termites and their management according to the region and type of domestic wooden cultural properties were identified. This was based on the survey reports of agencies conducting regular nationwide and regional monitoring of subterranean termites. In addition, using geographical information system (GIS) based on the survey contents, a map was constructed of termite infestation and its progress on 2,805 wooden cultural properties that were surveyed nationwide. Based on the map produced, a total of 486 cases of termite infestation were confirmed in wooden cultural properties during 2018-2019, of which 143 cases (approximately 29.4%) were confirmed to be owing to the invasion of termites in the ground and infestation of wood materials. A web platform and an application using a mapping application program interface were created to increase accessibility to the investigated damage status data. The methods employed by each institution for investigating and monitoring the invasion of termites in the ground included the use of detection dogs, visual observation, installation of wood specimens made of pine, and microwave equipment. However, it was confirmed that monitoring and survey methods were not applied to determine the territorial range of the subterranean termite colonies. Accordingly, the use of dyeing and mark-release-recapture methods were deemed necessary to understand the current status, such as calculating the scope of the target wooden cultural property, when monitoring subterranean termite colonies.