• Title/Summary/Keyword: chemical index

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Evaluation of Bio-Chemical Restoration Index at the Creation Site of Ecological Environmental Zone in Coastal Area (연안생태환경공간 조성지의 생물-화학적 복원지수 평가)

  • Lee, In-Cheol;Yi, Byung Ho;Park, So Young;Ryu, Cheong Ro
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.1B
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    • pp.161-168
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    • 2008
  • The ecological environmental zones in coastal area, like tidal flat and salt marsh, were gradually decreased due to large scale of coastal development projects, reclamation and so on. Therefore, the development of artificial tidal flat and salt marsh has been emphasized in coastal area as mitigation concept and studies on related this background has performed. But studies on the quantitative evaluation for degree of restoration were insufficient. In this paper, as a fundamental study for evaluation of restoration on the creation of ecological environmental zones in coastal area, it was conducted that the monitoring and experiment for bio-chemical factors (bio-diversity, population and biomass of macro-benthos, survival ratio of reed, the number of heterotrophic bacteria and physico-chemical characteristics such as COD, IL, TN, TP and pH) using a in-situ pilot plant of tidal flat (Zone. P1) and salt marsh (Zone. P2), which was distinguished by content of dredged soil, in Jinudo, Nakdong estuary. From results of this study, the restoration index (RI), for evaluation concerning degree of restoration on the creation of ecological environmental zones in coastal area, was suggested and quantitative evaluation was performed using a restoration index (RI).

On-line robust control of a system with dead time

  • Wu, Wen-Teng;Jang, Yu-Jen
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10b
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    • pp.902-906
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    • 1990
  • On-line robust control based on a stability index for time-delay systems has been developed. The purpose of the proposed design algorithm is to on-line tune a filter in the control loop. The problem of robust control with an incorrect given bound on the modeling error is investigated. Illustrative examples are presented to show the promise of the proposed method.

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Activated Clay Maunfacturing Studies(II) Studies on the Estimation of Acid Clay Structure (活性白土에 關한 硏究(제II報) 酸性白土의 構造 推定에 關하여)

  • Son, Sun-Kwan;Ko, Myoung-Won
    • Journal of the Korean Chemical Society
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    • v.14 no.4
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    • pp.309-319
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    • 1970
  • Composition of Acid Clay, the raw material for activated clay manufacturing, was investigated to develop useful data in deciding activation condition. Speculations on components and structure of activated clay were also made in order to see how included components of raw materials change during activation process. And a study was made on relations between structure of activated its adsorptivity. For this research, theremogravimetric analysis, X-ray differaction analysis and calculation of adsorptive index were carried out.

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Evanescent Wave-Based Fiber Bragg Grating Biosensors

  • Lee, Sang-Mae;Kim, Deug;Dagenais, Mario;Chryssis, Athanasios N.;Saini, Simarjeet Singh;Yi, Hyunmin;Bentley, William E.
    • Proceedings of the Optical Society of Korea Conference
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    • 2006.07a
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    • pp.399-400
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    • 2006
  • Etched fiber Bragg grating, Sensitivity of fiber-Bragg-grating sensors to index of surrounding, Hybridization of DNA

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Theoretical Studies on the Photo-Skinsensitizing Psoralens (I)

  • Ja-Hong Kim;Sang-Chul Shim
    • Bulletin of the Korean Chemical Society
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    • v.1 no.2
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    • pp.71-73
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    • 1980
  • The electronic structure of photo-skinsensitizing psoralens has been investigated by the FMO method. On the basis of theoretical calculations, optimum value of indices (Ft=0.33) has been proposed which corresponds to the sum of frontier electron density. The results indicate that this index is closely correlated with photo-skinsensitizing carcinogenic activity. The formations of molecular complexes between DNA and photo-skinsensitizing carcinogens is discussed in terms of charge transfer interactions.

Studies on the Formation of Poly(ethylene 2,6-naphthalate). 1. Polycondensation Catalyzed by Various Metal Compounds

  • 박상순;임승순
    • Bulletin of the Korean Chemical Society
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    • v.16 no.11
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    • pp.1093-1099
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    • 1995
  • The polycondensations of bis(2-hydroxyethyl) naphthalate were kinetically investigated in the presence of various metallic compounds as catalysts at 295 ℃. The effect of the catalyst nature in the polycondensation has been studied. The order of catalytic activity on the formation of poly(ethylene 2,6-naphthalate) was found to be related to the stability constants which are indicated in an index of the catalytic activity.

Synthesis and Physical Properties of Ophthalmic Copolymer Containing 4-fluorostyrene (4-Fluorostyrene을 포함하는 안의료용 고분자 합성 및 물리적 특성)

  • Kim, Tae-Hun;Sung, A-Young
    • Journal of the Korean Chemical Society
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    • v.54 no.3
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    • pp.317-322
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    • 2010
  • This study used 4-fluorostyrene with the cross-linker EGDMA (ethylene glycol dimethacrylate), HEMA (2-hydroxyethyl methacrylate) and the initiator AIBN (azobisisobutyronitrile) for copolymerization. Measurement of the physical properties of the copolymerized polymer showed that the water content was 19.98 ~ 31.08%, refractive index 1.443 ~ 1.475, visible transmittance 87 ~ 93% and tensile strength 0.246 ~ 0.311 kgf while the contact angle showed a distribution between $54.14^{\circ}$ and $66.95^{\circ}$. Therefore, the ophthalmic material produced using 4-fluorostyrene satisfied the basic physical properties required for contact lenses and also showed an increase in wettability and refractive index while having no significant change in water content with relation to styrene. Based on the results of this study, the produced copolymer is suitable for use as a material to high refractive index and wettability contact lenses.