• 제목/요약/키워드: chemical indicator

검색결과 330건 처리시간 0.025초

Hybridization by an Electrical Force and Electrochemical Genome Detection Using an Indicator-free DNA on a Microelectrode-array DNA Chip

  • Choi, Yong-Sung;Lee, Kyung-Sup;Park, Dae-Hee
    • Bulletin of the Korean Chemical Society
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    • 제26권3호
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    • pp.379-383
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    • 2005
  • This research aims to develop DNA chip array without an indicator. We fabricated microelectrode array by photolithography technology. Several DNA probes were immobilized on an electrode. Then, indicator-free target DNA was hybridized by an electrical force and measured electrochemically. Cyclic-voltammograms (CVs) showed a difference between DNA probe and mismatched DNA in an anodic peak. Immobilization of probe DNA and hybridization of target DNA could be confirmed by fluorescent. This indicator-free DNA chip microarray resulted in the sequence-specific detection of the target DNA quantitatively ranging from $10^{-18}\;M\;to\;10^{-5}$ M in the buffer solution. This indicator-free DNA chip resulted in a sequence-specific detection of the target DNA.

모의실험을 통한 편의점 판매용 김밥 도시락의 유통기한 예측 (The Predicton of the Shelf-life of Packaged Meals (Kim Pab) Marketed in Covenience Stores Using Simulation Study)

  • 곽동경;김성희
    • 한국식품위생안전성학회지
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    • 제11권3호
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    • pp.189-196
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    • 1996
  • Based on microbiological-chemical test results under simulated time-temperature conditions, total plate count, coliform, and volatile basic nitrogen were selected as effective quality indicators for estimating probable shelf-life on Kim Pab dosirak marketed in convenience stores, and shelf-life at each storage temperature was calculated from regression equation between effective quality indicator standard limit and storage time. Estimated shelf lives of Kim Pab Dosirak were 17, 3 and 2 hours respectively under 1$0^{\circ}C$, 2$0^{\circ}C$ and 3$0^{\circ}C$. Because shelf-life was especially affected by intial values, regression analysis between initial effective quality indicator values and storage hours was performed for the estimation of probable shelf-life on Kim Pab during storage at 10, 20, or 3$0^{\circ}C$.

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Determination of the Dissociation Constant of Thymol Blue with Diode-Laser/Fiber-Optic Thermal Lensing Spectroscopy

  • 김성호;노영순
    • Bulletin of the Korean Chemical Society
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    • 제19권8호
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    • pp.822-824
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    • 1998
  • The simple and convenient measurement of the dissociation constant of an indicator, thymol blue, was achieved by using a portable diode-laser/fiber-optic thermal lensing spectroscopy, which consisted of a visible diode laser, a photodiode, and an optical fiber. It gives comparable results to the cited value obtained from a conventional UV/VIS spectroscopy.

Insect natural enemies as bioindicators in rice paddies

  • Ueno, Takatoshi
    • 농업과학연구
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    • 제39권4호
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    • pp.545-553
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    • 2012
  • In Asia, including Japan and Korea, rice paddies occupy the largest cultivated area in agricultural land. Rice paddies provide the habitats for many organisms including endemic species, sustaining high biodiversity. Insect natural enemies inhabiting rice paddies have an important function for rice production as agents of 'ecosystem services' because they play a major role in suppressing rice pests. The diversity and abundance of natural enemies can be a good index reflecting the 'healthiness' of agro-ecosystem services in rice paddies. The present study investigates whether insect natural enemies could be good biological indicators for general arthropod biodiversity and agricultural practice. First, the concept of ideal bio-indicators was summarized. The strategy to explore and select such bio-indicators was then proposed. Lastly, field survey was made to evaluate the abundance and biodiversity of natural enemies in Japanese rice paddies where chemical inputs, i.e., insecticide use, were different. The results showed that reduction of chemical inputs led to an increase in species richness or diversity of natural enemies including parasitoids and predators. Then, the data were analyzed to examine suitable indicator species to assess environmental soundness of agricultural practice and biodiversity in rice paddies. The density of several species of natural enemies did respond both to pesticide use and to general arthropod biodiversity. The analyses thus have indicated that natural enemies can be suitable as bio-indicators. Usefulness of indicator species in rice paddies is discussed in the context of ecologically sound agriculture.

스팀 멸균지시제 자동판독시스템 개발 (Development of Automatic Reading System for Steam Sterilization Indicator)

  • 송혁;김정래;이우철
    • 한국전자통신학회논문지
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    • 제17권4호
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    • pp.709-714
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    • 2022
  • 스팀멸균에서 사용되는 스팀 멸균지시제(Steam sterilization Indicator)의 색변화 성공여부를 현재는 사람의 눈을 의존해서 판독하고 있다. 멸균의 성공여부에 대한 색변화의 결과는 숙련된 훈련을 받은 사람만이 정확하게 판독해서 판정을 내릴 수 있다. 스팀 멸균지시제에 대한 자동 판독시스템을 개발하여 기존 인간의 눈으로 의존해서 판독했던 방식을 기존보다 정확하고, 누구나 쉽게 판독하는 시스템을 개발하였다.

지시약의 등흡광점을 이용한 용액의 pH 측정 (pH Measurement Using Isosbestic Point of Indicator)

  • 최원형;허호장
    • 대한화학회지
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    • 제33권2호
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    • pp.203-207
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    • 1989
  • 지시약 메틸레드 용액을 시료용액에 첨가하고 지시약의 산형의 최대흡수파장과 염기형의 최대 흡수파장 및 등흡광점에서 이 시료액 흡광도를 측정하였다. 이를 측정한 흡광도로부터 이 용액의 pH를 계산하였다. 등흡광점에서 흡광도 범위를 0.1내지 0.3으로 유지하고 시료용액의 pH가 $pK_I{\pm}1$내에서, pH측정오차는 ${\pm}$0.08pH 단위 이내이었다.

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셀룰로오스 나노 섬유를 활용한 리튬 흡착 및 추출 연구 (Study on Lithium Extraction Using Cellulose Nanofiber)

  • 정래일;최진섭
    • 한국표면공학회지
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    • 제57권1호
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    • pp.31-37
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    • 2024
  • The surge in demand for lithium is primarily fueled by the expanding electric vehicle market, the necessity for renewable energy storage, and governmental initiatives aimed at achieving carbon neutrality. This study proposes a straightforward method for lithium extraction utilizing cellulose nanofiber (CNF) via a vacuum filtration process. This approach yields a porous CNF film, showcasing its potential utility as a lithium extractor and indicator. Given its abundance and eco-friendly characteristics, cellulose nanofiber (CNF) emerges as a material offering both economic and environmental advantages over traditional lithium extraction techniques. Hence, this research not only contributes to lithium recovery but also presents a sustainable solution to meet the growing demand for lithium in energy storage technologies.