• Title/Summary/Keyword: 자당

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A Strip Sensor Based on PbO2/Carbon Paste Electrode to Determine Sweetener Contents in Fruits (이산화납/탄소 반죽 전극을 이용한 과당 농도 측정 스트립센서)

  • Lee, Jae Seon;Cho, Joo Young;Heo, Min;Lim, Woo-Jin;Lee, Sang Eun;Nam, Hakhyun;Cha, Geun Sig;Shin, Jae Ho
    • Journal of the Korean Electrochemical Society
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    • v.17 no.2
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    • pp.130-137
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    • 2014
  • A strip sensor based on $PbO_2$/carbon paste electrode was prepared by a screen-printing method, and employed to electrochemically determine the concentration of fruit sweeteners(i.e. glucose, sucrose, and fructose). The $PbO_2$/carbon paste electrode could monitor electrocatalytic oxidation of organic compounds such as carbohydrates, and measure the levels of natural sweeteners without enzyme. Severe interference from ascorbic acid was effectively reduced by modifying the electrode surface with a Nafion membrane. The response level of the Nafion/$PbO_2$/carbon paste electrode increased in the order of fructose, sucrose, and glucose, which corresponds to the order of sweetness perceived by humans.

Fast Neutron Dosimetry in Criticality Accidents (핵임계사고시(核臨界事故時)에 있어서 속중성자선량(速中性子線量)의 해석(解析))

  • Ro, Seung-Gy;Yook, Chong-Chul
    • Journal of Radiation Protection and Research
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    • v.1 no.1
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    • pp.1-9
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    • 1976
  • A suggestion has been made for neutron dosimetric techniques using activation and threshold detectors in criticality accidents. Neutron dosimetrical parameters, namely, the fission spectrum-averaged cross-sections of some threshold reactions and fluence-to-dose conversion factors have been calculated by the use of an electronic computer. It appears that detectors having comparatively high threshold energy give more fine information on spectral deformation in criticality accidents, while detectors with low threshold energy are of usefulness for measuring fast neutron fluence regardless of fissioning types. Unexpectedly it is found that the fission spectrum-averaged cross sections of the $^{32}S(n,\;p)^{32}P$ reaction is not sensitive to analytical forms of fission neutron spectrum: the modified Cran-berg and Maxwellian forms. In addition, the fluence-to-dose conversion factors seem to be insensitive to both spectral functions and fissioning types.

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A Study of Biological Hydrogen Gas Production under Anaerobic Fermentation (혐기성 발효에 의한 생물학적 수소생산에 관한 연구)

  • Yoon, Woo-Hyun;Kim, Hyun-Kab;Lee, Tae-Jin
    • Journal of the Korea Organic Resources Recycling Association
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    • v.14 no.1
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    • pp.131-138
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    • 2006
  • In this study, the optimum condition of pH was investigated on the hydrogen gas production under anaerobic fermentation process. The results of the experiment showed that the optimum condition was observed at pH 6, resulting in 1175.87 mL/L of hydrogen gas production rate and 22.51% theoretical hydrogen conversion ratio. Hydrogen gas production rate and theoretical hydrogen conversion ratio were 901.77 mL/L and 17.48 % respectively at pH 5. At pH 7 and 8, the production rate of hydrogen gas was little low as 82.15 mL/L. Among the organic acids from the sucrose fermentation, propionate was observed as the dominant acid at pH 7 and 8 but butyrate was the dominant at pH 5 and 6.

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Effect of Medium Component on Plant Regeneration via Adventitious Bud Formation from Leaf Explant Cultures of Strawberry (Fragaria ananassa Duch.) (딸기 (Fragaria ananassa Duch.) 잎 절편체 배양으로부터 부정아 형성을 통한 식물체 재생)

  • 조덕이;소웅영;정원일
    • Korean Journal of Plant Tissue Culture
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    • v.28 no.3
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    • pp.171-178
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    • 2001
  • This study was investigated to establish a regeneration system of plant via adventitious bud formation from leaf explant cultures of strawberry (Fragaria ananassa Duch). Effects of plant growth regulators (2,4-D, BAP), agar sucrose and myo-inositol on adventitious bud formation were investigated. When the leaf explants were cultured on MS medium supplemented with 0.1 mg/L 2,4-D and 3 mg/L BAP, the adventitious bud formation was most promoted. The adventitious bud formation was not induced from leaf explants cultured on MS medium containing 2,4-D alone. Adventitious bud formation was enhanced to almost 3 times on medium with low level of agar concentration (0.4%) in comparison with those on the medium with high level of agar (1%), but almost of shoot was vitrificated on the medium. Therefore, the normal adventitious bud formation from leaf explants was most effective on the medium containing 0.05 mg/L 2,4-D,1 mg/L BAP, 0.8% agar, 30 g/L sucrose and 100 mg/L myo-inositol. Thus, the mass propagation of healthy strawberry could be established using leaf explants.

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A Study on the Purification Process of Methyl Fructoside by Liquid Chromatography (액체 크로마토그래피에 의한 메틸프룩토시드의 분리공정 연구)

  • 허주형;유인상김해성
    • KSBB Journal
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    • v.11 no.5
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    • pp.529-535
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    • 1996
  • Methyl frucloside was purified from the aqueous sugar/methyl fructoside solution by liquid chromatography using Amberlite IRA-900, strong anion-exchange resin. The optimum operating conditions, resolution and productivity of methyl fructoside were discussed to evaluate the practical feasibility of the proposed chromatographic separation process of methyl fructoside which is useful as a new starting material for sugar ester synthesis. The linear chromatography model with HETP was well applied to the chromatographic separation process of methyl fructoside and the theoretical solution successfully predicted the elution chromatogram of methyl fructoside and sucrose at different superficial linear velocity of eluent for rectangular feed with different loading volume of packed bed. The optimum operating conditions were found to be 75% with the loading volume of packed bed at 1.13 cm/min of the superficial linear velocity at $60^{\circ}C$, and gave the productivity of methyl fructoside of 7 mg/g-resin/h with the resolution of 1.1.

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Taxol Production in Taxus Cell Cultures : 2. Effects of Sugar Concentration (주목 세포배양에 의한 Taxol 생산:2. 당농도의 영향)

  • 김진훈;박인석
    • KSBB Journal
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    • v.9 no.5
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    • pp.450-456
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    • 1994
  • The effects of sucrose on cell growth and anticancer drug taxol production were investigated in cell suspension cultures of Taxus cuspidata. The cells were cultured at various concentrations of sucrose (20 to $100g/\ell$). The highest specific growth rata was achieved at $40g/\ell$ of sucrose as 0.076 day-1 and the highest final cell density, 34 g DCW/$\ell$ after 25 days of culture, was obtained at $60g/\ell$ of sucrose. The cell yield(Yx/s) was found to be 0.55g cell/g sucrose and doubling time (Td) was 9.12 day. High concentration of sucrose (80, $100g/\ell$) and the addition of osmoticum enhanced the production of taxol significantly. The maximum taxol production was $1.36mg/\ell$ at $80g/\ell$ of sucrose, which was 0.01% as a specific content.

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Effects of Carbon, Nitrogen Sources and pH on Direct Somatic Embryogenesis in Liquid Culture of Rehmannia glutinosa Lib. (지황의 액체배양에서 탄소원.질소원 및 pH가 직접 체세포배 형성에 미치는 영향)

  • Chae, Young-Am;Park, Ju-Hyun
    • Korean Journal of Medicinal Crop Science
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    • v.7 no.1
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    • pp.1-6
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    • 1999
  • Basic informations for direct somatic embryo formation in Rehmannja glutinosa Lib. were obtained in 500ml erlenmyer flask. The ratio of ammonium to nitrate nitrogen of 825(mg/l) : 1900(mg/l) was proper condition for somatic embryo formation from stem and petiole explants and 3% sucrose was the most effective carbon source. Full strength MS medium with 2mg/l BA was better than LS medium for somatic embryogenesis. The initial pH 5.7 of medium(full strength MS with 2.0mg/l BA and 0.1mg/l NAA) was good for embryo production. Potassium ion was taken up rapidly within 2 weeks. while $Ca^{++}$ and $Mg^{++}$ ion contents were almost constant during culture period. Sucrose hydrolysis occurred throughout the culture, while glucose and fructose were absorbed simultaneously from the third week of culture.

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Share Renewal Scheme in Proactive Secret Sharing for Threshold Cryptosystem (임계 암호시스템 구현을 위한 능동적 비밀 분산에서의 공유 갱신 방법)

  • 이윤호;김희열;정병천;이재원;윤현수
    • Journal of KIISE:Computer Systems and Theory
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    • v.30 no.5_6
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    • pp.239-249
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    • 2003
  • The secret sharing is the basic concept of the threshold cryptosystem and has an important position in the modern cryptography. At 1995, Jarecki proposed the proactive secret sharing to be a solution of existing the mobile adversary and also proposed the share renewal scheme for (k, n) threshold scheme. For n participants in the protocol, his method needs $O(n^2)$ modular exponentiation per one participant. It is very high computational cost and is not fit for the scalable cryptosystem. In this paper, we propose the efficient share renewal scheme that need only O(n) modular exponentiation per participant. And we prove our scheme is secure if less than img ${\frac{1}{2}}$ n-1 adversaries exist and they are static adversary.

Effects of Emulsifiers on the Properties of White Layer Cakes Prepared from Geurumil Flour (그루밀가루의 White Layer Cake 적성과 유화제 첨가 효과)

  • 경문식;장학길;이영택
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.5
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    • pp.877-881
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    • 2001
  • A domestic wheat variety (Geurumil flour) was evaluated for the properties of white layer cake, and compared to a commercial soft wheat flour. Geurumil flour contained more protein, ash, and lipid contents than commercial soft wheat flour. Very little difference in cake batter pH was observed between soft wheat flour and Geurumil flour, and the addition of emulsifiers tended to decrease the pH of Geurumil cake batter The specific gravity of the cake batter was lower in Geurumil flour than in soft wheat flour, and decreased effectively by the addition of emulsifiers due to batter aeration. Specific loaf volume was influenced by the addition of emulsifiers and demonstrated the highest values at the level of 1 ~ 2%. Addition of Ester-400 (monoglyceride) showed better cake properties in terms of volume, symmetry and uniformity index than sucrose-fatty acid ester did, and thus appeared to be more effective in improving baking performance. The changes in firmness of cakes during storage at $25^{\circ}C$ were observed, and Ester-400 showed some Positive effects on retarding cake staling.

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IN VITRO STUDY OF CARIOGENIC POTENTIAL OF INFANT CONFECTIONARIES (유아용 과자의 우식유발능에 관한 생체 외 연구)

  • Song, Ji-Hyon;Lee, Kwang-Hee;Kim, Dae-Eup;Ra, Ji-Young;Lee, Dong-Jin;An, So-Youn
    • Journal of the korean academy of Pediatric Dentistry
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    • v.35 no.1
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    • pp.39-46
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    • 2008
  • The purpose of this study was to assess the cariogenic potential of infant confectionaries. In vitro, as compaired with 10% sucrose solution and whole bovine milk. Buffering capability were determined by amount of 0.1N lactic acid consumed to titrate the 50ml specimen solutions to pH 4.0. The pH of the specimen solution inoculated by streptococcus mutans was measured by pH meter and the surface microhardness tester, before and after 48 hours incubation. The buffering capacity of infant confectionaries was higher than that of sucrose solution and lower than that of milk, and there were significant difference between infant confectionaries(p<0.05). The pH of infant confectionaries after 48 hours incubation was similar to 10% sucrose solution, and there were significant difference between infant confectionaries and milk(p<0.05). The microhardness change of primary tooth enamel of infant confectionaries group after 48 hours incubation was similar to that of 10% sucrose solution, and there were significant difference between infant confectionaries and milk(p<0.05). In conclusion, infant confectionaries seemed to have the ability to cause dental caries in primary teeth, and there were significant differences of cariogenic potential among infant confectionaries. Cooperative efforts of dentistry and manufacturers to reduce the cariogenic potential of infant confectionaries would be necessary to prevent the early childhood caries in children.

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