• 제목/요약/키워드: retention time

검색결과 1,731건 처리시간 0.035초

RP-HPLC법에 의한 무우의 매운 성분인 4-methylthio-3-butenyl isothiocyanate의 분리 및 정제 (Purification of 4-Methylthio-3-butenyl isothiocyanate the Pungent Principle in Radish Roots by RP-HPLC)

  • 김미리;이혜수
    • 한국식품조리과학회지
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    • 제2권2호
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    • pp.16-20
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    • 1986
  • 무우 속의 매운 맛 성분을 용매추출법 ($CCl_4$,사용)으로 분리하여 RP-HPLC법에 의해 정제한 후에 관능검사에 의해 pungency test를 하고, UV spectrum분석, GC/MC 분석을 수행한 결과 4-methylthio-3-butenyl isothiocyanate 임을 확인하였다. RP-HPLC에서 mobile Phase로 70% acetonitrile을 사용하였는데, 정제된 4-methylthio-3-butenyl isothiocfanate는 단일 peak로 분리되어 나왔고 이때의 retention time은 5.2분이였다. 아울러 RP-TLC에서 Rf치는 0.9이었다.

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Biomass 자원의 활용 (I) - 율추의 유효이용을 위한 화학적 조성분의 HPLC 분석 - (Utilization of Biomass Resources(I) - HPLC Analysis of Chemical Components for Utilization of Chestnut Inner Bark -)

  • 김윤근;조종수
    • Journal of the Korean Wood Science and Technology
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    • 제32권2호
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    • pp.58-64
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    • 2004
  • 임산바이오매스 자원 이용의 일환으로 율추(栗皺) 열수추출물의 디에틸에테르 가용부의 HPLC 분석결과, 표준물질과의 retention time이 일치한 것을 RI detector로 얻어진 각 피크의 스펙트럼을 표준물질과 비교하고, 순도를 확인하는 방법으로 피크의 동정을 실시하였다. 피크의 동정 결과, phenolic acids와 aldehyde류로는 gallic acid, 3,5-dihydroxybenzoic acid, 2,4,6-trihydroxybenzoic acid, 그리고 protocatechualdehyde이었으며, flavonoids는 catechin과 epicatechin으로 모두 6종이 확인되었다.

물질 보류 : 안료 코팅 처리를 위한 새로운 시도 (Material Retention: A Novel Approach to Performance of Pigment Coating Colors)

  • McKenzie, Ken;Rutanen, Anne;Lehtovuori, Jukka;Ahtikari, Jaana;Piilola, Teuvo
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2008년도 제33회 펄프종이기술 국제세미나
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    • pp.47-70
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    • 2008
  • Cost efficiency is today the primary requirement in the paper and board industry. This has led therefore, to a greater preponderance of products with specifically designed functionality to take account of current industry needs. Continually increasing machine coating speeds together with these new coating colour components have put more emphasis on the importance of the correct rheology and water retention of the coating colours to achieve good runnability and end product quality. In the coating process, some penetration of the aqueous phase, to the base paper or board must occur to anchor the pre-coating to the base or the topcoat to the pre-coat. The aqueous phase acts as a vehicle not only for the binder, but also for the other components. If this water or material penetration is not controlled, there will be excessive material shift from the coating colour to the base, before immobilization of the coating colour will stop this migration. This can result in poor machine runnability, unstable system and uneven coating layer, impacting print quality. The performance of rheology modifiers or thickeners on the coating color have tended to be evaluated by the term, "water retention". This simple term is not sufficient to explain their performance changes during coating. In this paper we are introducing a new concept of "material retention", which takes note of the total composition of the coating colour material and therefore goes beyond the concept of only water retention. Controlled material retention leads to a more uniform z-directional distribution of coating colour components. The changes that can be made to z-directional uniformity will have positive effects on print quality as measured by surface strength, ink setting properties, print gloss, mottling tendency. Optical properties, such as light scattering, whiteness and light fastness delivery should also be improved. Additionally, controlled material retention minimizes changes to the coating colour with time in re-circulation giving less fluctuation in quality in the machine direction since it more closely resembles fresh coating for longer periods. Use of the material retention concept enables paper and board producers to have more stable runnability (i.e. lower process costs), improved end product quality (i.e. better performance of used chemicals) and/or optimized use of coating colour components (i.e. lower total formulation cost)

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소생재 도포 후 고온 유지시간 및 양생방법 변화가 Fly Ash 다량치환 모르타르의 압축강도에 미치는 영향 (Effects of High Temperature Maintenance Time and Curing Method on Compressive Strength of FA Large Volume Replacement Mortar after Application of Resuscitation Material)

  • 최윤호;이혁주;이영준;현승용;한민철;한천구
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2019년도 추계 학술논문 발표대회
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    • pp.141-142
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    • 2019
  • In this study, we conducted a comparative analysis of the effects of retention time and resuscitation method on the degree of resuscitation after reapplying mortar with much FA replacement. Results After applying NaOH to the top surface of 60 % FA-substituted mortar, the degree of resuscitation at $40^{\circ}C$ was high enough to increase the overall curing time, but there was no significant difference. However, with regard to the curing method, middle curing showed the greatest manifestation, followed by wrapping and underwater curing, but there was no significant difference. The resuscitation level on the 28th of the lumber was found to be revived to about 70~80 % at around 30 % without resuscitation.

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마우스에서 스쿠알렌에 의한 방사성수은 억제 효과 (Inhibition of radiomercury(Hg-203) by squalene in mice)

  • 이경희;김영호;김종세
    • Journal of Radiation Protection and Research
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    • 제25권1호
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    • pp.45-51
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    • 2000
  • 본 연구의 목적은 마우스 주요 조직내의 방사성수은 침착을 알아보기 위하여 실험을 하였다. 건강한 ICR계 수컷 마우스를 사용하였고 두 개의 실험군을 설정하였다. 실험군은 방사성수은(0.005 uCi/b.w.)을 단독처치하고 스쿠알렌(200mg/kg)을 1일 2회씩 구강 처치하였다. 대조군은 실험군과 동일한 방법으로 방사성수은만 단독처치 하였다. 결과적으로 주요 침착 장기는 신장, 간, 혈액, 심장, 두개골이었다. 대조군의 경우 모든 장기에서 6시간째에 가장 높은 방사성수은 침착을 보였으나, 스쿠알렌을 처치한 실험군의 경우는 6시간째에 방사성침착이 유의하게 억제됨을 관찰 할 수 있었다(p<0.05). 결론적으로, 스쿠알렌이 방사성수은의 조직 침착을 억제시키는데 효과가 있는 것으로 사료된다.

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기능적 변연형성에 의한 총의치 인상채득법 (COMPLETE DENTURE IMPRESSION BY A SIMPLE FUNCTIONAL BORDER MODING)

  • 황의환;이정열;신상완;서규원
    • 대한치과보철학회지
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    • 제32권4호
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    • pp.515-525
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    • 1994
  • Impression taking is a very important procedure in complete denture fabrication for reproduction of the tissue surface from which obtain retention and support of denture base. Therefore, we can not construct retentive denture without precise impression taking. Retention in complete denture can be obtained by the closest contact between denture base and underlying tissue, maximum coverage and proper displacement of the border tissue for peripheral sealing. Therefore, it is very important to take impression of the border tissue displaced properly. Nowadays, impression of the border tissue is mainly taken by the border molding techniques by means of manual muscle trimming, but due to various muscle trimming methods as clinicians, it is difficult to select proper method. This technique is also bodersome to do and time-consuming procedure. Retention is also likely reduced, because of the recording excessive muscle movement than actural physiological border tissue movement. Therefore, the impression technique that records actual physiologic functional muscle movement is helpful to increase denture retention and easy to do. We named this technique a functional border molding technique. This technique is originally introduced by D. J. Neill and R. I. Nairn in 1968. We tried to fabricate complete denture by the impression by means of functional border molding technique for better retention and the convenience, and obtained good results.

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연속회분식반응조 공정에서 슬러지 체류시간과 중금속 독성의 관계 (Relationship between Toxicity of Heavy Metals and Sludge Retention Time in Sequencing Batch Reactor Process)

  • 김금용;조영철;이상일
    • 대한환경공학회지
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    • 제29권3호
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    • pp.283-288
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    • 2007
  • 연속회분식반응조(SBR) 공정에서 슬러지 체류시간(SRT)에 따른 중금속의 독성도 변화를 측정하였다. 중금속은 구리(Cu), 카드뮴(Cd) 및 아연(Zn)을 사용하였고, SRT는 $2\sim30$일로 변화시켰으며, 독성도는 INT-dehydrogenase 활성도의 변화로 측정하였다. 중금속의 농도가 증가함에 따라 독성도가 증가하였으며, Cu가 Zn 및 Cd 보다 독성도가 높았다. SRT를 변화시켰을 때 $IC_{50}$ 값이 Cu의 경우 $0.37\sim1.96$ mg/L의 범위를 나타내었으며, Cd의 경우는 $15.4\sim16.9$ mg/L를 나타내었다. 또한 Zn의 경우는 $9.70\sim23.4$ mg/L의 범위를 나타내었다. Cu와 Zn의 경우, SRT가 증가함에 따라 독성이 감소하였으며, 이는 긴 SRT에서 세포외 중합체의 농도가 증가하기 때문인 것으로 판단된다. 따라서 중금속을 포함한 산업폐수를 처리하는 SBR 공정에서 SRT를 길게 운영하는 것이 바람직할 것으로 판단된다.

연속식 미생물연료전지 성능에 미치는 운전변수의 영향 (Effects of operating parameters on the performance of continuous flow microbial fuel cell)

  • 정재우;최영대;이명은;송영채;우정희;유규선;이채영
    • 상하수도학회지
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    • 제27권4호
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    • pp.489-494
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    • 2013
  • Effects of operating parameters such as hydraulic retention time(HRT), recycle ratio and influent COD concentration on the performance of a continuous flow microbial fuel cell(MFC) were investigated. Decrease of HRT improved mass transfer of substrate to electrogenic microorganisms, therefore resulting in increased electrode voltage and power generation of MFC. Increase of HRT promoted COD removal by elongating retention time for COD removal in MFC. Recycling of effluent increased the COD removal and coulombic efficiencies by returning suspended microorganisms into MFC. Increase of influent COD enhanced COD removal due to the improved mass transfer of substrate. Decrease of coulombic efficiency by the increase of the HRT and influent COD concentration indicated that they enhanced the activities of fermentative bacteria.