• Title/Summary/Keyword: Shim

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Photocycloaddition Reaction of 1,2-Bispyrazylethylene to Tetracyanoethylene

  • Shim, Sang-Chul;Shim, Hyun-Kwan
    • Bulletin of the Korean Chemical Society
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    • v.1 no.4
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    • pp.123-126
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    • 1980
  • Benzene solution of trans-1,2-bispyrazylethylene and electron deficient olefin, tetracyanoethylene, as a ${\pi}$-acceptor gave 1,2-bispyrazyl-3,3,4,4-tetracyanocyclobutane, a 2${\pi}$ + 2${\pi}$ cycloaddition product, on irradiation with 350 nm UV light. Fluorescence studies revealed the reaction to proceed through a singlet exciplex. The fluorescence of trans-1,2-bispyrazylethylene was quenched very efficiently by tetracyanoethylene with the quenching constant of 1.6 ${\times}$ 10$^{10}$M$^{-1}$s$^{-1}$ while electron rich olefin, tetramethylethylene, did not quench the fluorescence of bispyrazylethylene.

Photoaddition Reaction of 5,7-Dimethoxycoumarin with Adenosine

  • Cho, Tae-Heung;Shim, Hyun-Kwan;Shim, Sang-Chul
    • Bulletin of the Korean Chemical Society
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    • v.8 no.3
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    • pp.206-211
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    • 1987
  • The photoreaction of 5,7-dimethoxycoumarin with adenosine has been carried out in a dry film state. The mixture of DMC and adenosine was irradiated with 350 nm UV light and two major products were isolated. The structure was determined by various spectroscopic measurements involving $^{13}C$ nuclear magnetic resonance and fast atom bombardment mass spectrometry. These addition products were produced by covalent bond formation between the pyrone ring at carbon 3 or 4 and the sugar ring moiety of adenosine at carbon 5'.

Optimization for the Alcohol Fermentation of Hydrolyzed Vegetable Protein(HVP) Soy Sauce by Saccharomyces Rouxii (Saccharomyces rouxii에 의한 아미노산 간장의 알코올 발효)

  • Choi, Soo-Bok;Kwon, Oh-Sung;Nam, Hee-Sop;Shin, Zae-Ik;Yang, Han-Chul
    • Korean Journal of Food Science and Technology
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    • v.24 no.4
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    • pp.330-334
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    • 1992
  • In order to improve the flavor quality of a soy sauce, hydrolyzed vegetable protein(HVP), it was subjected to ethanol fermentation by Saccharomyces rouxii and the effect of several environmental factors on the alcohol fermentation of S. rouxii in HVP was investigated. The NaCl content of HVP affected significantly on the growth of S. rouxii, showing growth inhibition above the value of 6%(w/v). The growth of S. rouxii was not inhibited by the coloring materials of HVP. The proper initial concentration of glucose for the growth of the yeast was ranged from 15%(w/v) to 25%(w/v). The optimal temperature for the growth and alcohol production was $25^{\circ}C$. The growth increased with the increasing rate of aeration, while alcohol concentration of fermented HVP showed its maximum value of 4.2%(w/v) at the aeration rate of 0.5 vvm.

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Studies on the Separation of Taste Components from Sea Tangle (Laminaria japonica) Extract by Cross Flow Ultrafiltration (한외여과에 의한 다시마 정미성분 분리에 대한 연구)

  • Lee, Ho-Bong;Lee, Seung-Ryeol;Chang, Young-Sang;Shin, Zae-Ik
    • Korean Journal of Food Science and Technology
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    • v.24 no.3
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    • pp.199-203
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    • 1992
  • This study was aimed to optimize the required condition for recovering the low soluble taste component obtained from sea tangle extract using ultrafiltration, and to investigate effects of membrane type, temperature, transmembrane pressure and flow rate respectively. We also compared relationship between the profile of permeate flux and the recovery yield of taste component under the selected optimal condition using ultrafiltration and diafiltration. Hydrophobic GR 51 PP membrane kept higher average permeate flux than hydrophilic FS membrane, and average permeate flux also had increasing tendency in relation to rising flow rate but it showed limit value of 3.7 l/min. Average permeate flux decreased as transmembrane pressure increased but it showed little change with rising temperature. Investigation upon average permeate flux, total dissolved solid and recovery yield of taste components using ultrafiltration and diafiltration resulted in relatively higher recovery yield in ultrafiltration. Compared ultrafiltration and diafiltration, average permeate flux was lower in ultrafiltration.

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Applying tilt mechanism for high-resolution image acquisition (고해상도 영상 획득을 위한 틸트 메커니즘 적용 기법)

  • Song, Chun-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.12
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    • pp.31-37
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    • 2014
  • In this paper, to compensate the degraded performance in high-resolution infrared sensor due to assembling error, the influence of each component was evaluated through the sensitivity analysis of lens assembly, axis mirror, and detector and also suggested detector tilt mechanism for compensation. 3 detector tilt mechanisms were investigated. The first one is 'Shim plate' method which is applying shim on installing plane. The second one is 'Tilting screw' method that is using tilt screw for adjusting detection plane. The last one is 'Micrometer head' method that is installing micrometer on detection plane and acquiring quantitative data. Based on the investigation result, 'Tilting screw' method was applied due to ease of user control, small volume, and real-time controllability, thereby we could acquire high-resolution infrared images. The research result shows that the tilting mechanism is necessary technology for the implementation of high-resolution infrared imaging system.