• Title/Summary/Keyword: iodine reaction

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Hot- Water Soluble and Insoluble Materials of Waxy Black Rice Starch (찰흑미(상해항혈나) 전분의 열수가용성 및 불용성 물질)

  • Choi, Gyeong-Cheol;Na, Hwan-Sik;Oh, Geum-Soon;Kim, Sung-Kon;Kim, Kwan
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.2
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    • pp.219-222
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    • 2005
  • Some structural characteristics of hot-water soluble and insoluble starches (waxy black rice starch) were investigated. The hot-water soluble material content of waxy black rice starch was higher (16.6%) than that (13.4%) of Shinsunchalbyeo starch heated at 98$^{\circ}C$ for 8 min. The Amax and absorbance at 625 nm for hot-water soluble and insoluble material of waxy black rice starch were lower than those of Shinsunchalbyeo. Elution patterns of hot water soluble and insoluble materials by gel permeation chromatography (Sepharose CL-2B) were similar in both samples.

SAFETY STUDIES ON HYDROGEN PRODUCTION SYSTEM WITH A HIGH TEMPERATURE GAS-COOLED REACTOR

  • TAKEDA TETSUAKI
    • Nuclear Engineering and Technology
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    • v.37 no.6
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    • pp.537-556
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    • 2005
  • A primary-pipe rupture accident is one of the design-basis accidents of a High-Temperature Gas-cooled Reactor (HTGR). When the primary-pipe rupture accident occurs, air is expected to enter the reactor core from the breach and oxidize in-core graphite structures. This paper describes an experiment and analysis of the air ingress phenomena and the method fur the prevention of air ingress into the reactor during the primary-pipe rupture accident. The numerical results are in good agreement with the experimental ones regarding the density of the gas mixture, the concentration of each gas species produced by the graphite oxidation reaction and the onset time of the natural circulation of air. A hydrogen production system connected to the High-Temperature Engineering Test Reactor (HTTR) Is being designed to be able to produce hydrogen by themo-chemical iodine-Sulfur process, using a nuclear heat of 10 MW supplied by the HTTR. The HTTR hydrogen production system is first connected to a nuclear reactor in the world; hence a permeation test of hydrogen isotopes through heat exchanger is carried out to obtain detailed data for safety review and development of analytical codes. This paper also describes an overview of the hydrogen permeation test and permeability of hydrogen and deuterium of Hastelloy XR.

Optical properties of undoped and $Co^{2+}$-doped $Zn_4$$ GeSe_6$ single crystals ($Zn_4$$ GeSe_6$$Co^{2+}$를 첨가한 $Zn_4$$ GeSe_6$:$Co^{2+}$단결정의 광학적 특성)

  • 김덕태
    • Electrical & Electronic Materials
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    • v.10 no.2
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    • pp.105-112
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    • 1997
  • Undoped and Co$^{2+}$-doped Zn$_{4}$GeSe$_{6}$ single crystals were grown by the Chemical Transport Reaction method using iodine as a transporting agent. The crystal structure of these compounds determined by X-ray diffraction analysis was monoclinic structure. The direct energy gaps of these compounds were measured and the temperature dependence of the optical energy gap were closely investigated over the temperature range 10-290K. The temperature dependence of the optical energy gap is well presented by the Varshni equation. Also the optical absorption peaks of Zn$_{4}$GeSe$_{6}$ :Co$^{2+}$ single crystal observed, centered at 5437, 6079, 7142, 12950, 13462, 14786 and 15735 $cm^{-1}$ /, can be explained in terms of the electronic transitions of Co$^{2+}$ ions located at Td symmetry of the host materials. According to the crystal-field theory, the crystal-field, Racah and spin-orbit coupling parameters obtained from the absorption bands are given by Dq = 361$cm^{-1}$ /, B = 655$cm^{-1}$ / and .lambda. = 284$cm^{-1}$ / respectively.ively.

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Hall Effect of FeSi$_2$ Thin Film by Magnetic Field (FeSi$_2$박막 흘 효과의 자계의존성)

  • 이우선;김형곤;김남오;서용진
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.234-237
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    • 2001
  • FeSi$_2$/Si Layer were grown using FeSi$_2$, Si wafer by the chemical transport reaction method. The directoptical energy gap was found to be 0.871ev at 300 K. The Hall effect is a physical effect arising in matter carrying electric current in the presence of a magnetic field. The effect is named after the American physicist E. H. Hall, who discovered it in 1879. In this paper, we study electrical properties of FeSi$_2$/Si layer And then we measured Hall coefficient Hall mobility, carrier density and Hall voltage according to variation magnetic field and temperature, Because of important Part for it application Various phase of silicide is formed at the metal-Si interface when transition metal contacts to Si. Silicides belong to metallic or semiconducting according to their electrical and optical properties. Metallic silicides are used as gate electrodes or interconnections in VLSI devices. Semiconducting silicides can be used as a new material for IR detectors because of their narrow energy band gap.

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Hall Effect of $FeSi_2$ Thin Film by Temperature ($FeSi_2$박막 홀 효과의 온도의존성)

  • 이우선;김형곤;김남오;정헌상
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.230-233
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    • 2001
  • FeSi$_2$ Layer were grown using FeSi$_2$, Si wafer by the chemical transport reaction method. The directoptical energy gap was found to be 0.87leV at 300 K. The Hall effect is a Physical effect arising in matter carrying electric current in the presence of a magnetic field. The effect is named after the American physicist E.H. Hall, who discovered it in 1879. In this paper, we study electrical properties of FeSi$_2$/Si layer. And then we measured Hall coefficient Hall mobility, carrier density and Hall voltage according to variation magnetic field and temperature, Because of important part for it application various phase of silicide is formed at the metal-Si interface when transition metal contacts to Si. Silicides belong to metallic or semiconducting according to their electrical and optical properties. Metallic silicides are used as gate electrodes or interconnections in VLSI devices. Semiconducting silicides can be used as a new material for IR detectors because of their narrow energy band gap.

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Quantitative Analysis of Soluble Residues by Correction of Starch Content in Paperboard Grade (전분 함량 보정을 통한 판지류의 가용성 잔류물질 정량 분석)

  • Lim, Chae-Hoon;Park, Joung-Yoon;Lee, Tai-Ju;Um, Gi Jeung;Kim, Hyoung-Jin
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.45 no.6
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    • pp.78-87
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    • 2013
  • Even though the notice No. 2010-11 of the Ministry of Food and Drug Safety Administration that has been applied to analyze the content of the water soluble residue eluted from multi-layer paperboard was abolished in 2011, its application for the analysis on evaporation residue is still valid. There are very high possibilities that the noticed existing method gives the misleading result on the evaporation residue due to the water soluble starch eluted from the multi-layer paperboard. The quantitative analysis on water-soluble residue with starch content correction has been carried in the study using UV/Vis spectroscopy and HPLC. The UV/Vis spectroscopy absorbance analysis showed the large amount of the oxidized starch obtained from the aqueous residue eluted out of the multi-layer paperboard after the iodine, ${\alpha}$-amylase reaction, and starch hydrolysis. The residual content decreased by the correction through the enzyme hydrolysis.

Characteristics of Endosperm Starch of the Rice Mutant Lines Induced by Sodium Azide

  • Shin, Young-Seop;Park, Chlul-Soo;Seo, Yong-Weon;Jeung, Ji-Ung
    • Korean Journal of Breeding Science
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    • v.41 no.2
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    • pp.84-91
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    • 2009
  • Rice consumption per capta, in South Korea, has been decreased dramatically, owing to the changes of living patterns. Because of not only the major energy source of Korean people but also major income source of Korean farmers, diversifying end-use-quality of rice has been demanded. To the context, 'Suweon 472', a high yielding and early mature japonica line and released as 'Namilbyeo' to framers in 2002, was treated with a chemical mutagen, Sodium Azide to find endosperm mutant types. A total of nine endosperm mutat lines, including five waxy, one dull, two floury, and one white core type, were identified from the 3,542 mutatagen treated lines. Amylose contents, iodine reaction, disintegration in alkali solution, gelatinization in urea solution and amylogram properties of those nine endosperm mutant lines were evaluated to address the possibility as new genetic materials for diversifying rice quality of Korean japonica cultivars. All embryo mutants were clearly differentiated from their wild type, 'Suweon 472', in terms of physic-chemical properties evaluated. The endosperm mutant lines would be very useful in expanding untiliztation of rice through opening new rice markets of processed foods from Korean japonica rice.

Characteristics and Action Pattern of Alkaline Protease from Streptomyces gviseus HC-1141 (Streptomyces griseus HC-1141이 생성하는 Alkaline Protease의 특성 및 작용양상)

  • Choi, Cheong;Chung, Yung-Gun;Sung, Sam-Kyung;Choi, Kwang-Soo;Lee, Jae-Sung;Cho, Young-Je;Chun, Sung-Sook
    • Microbiology and Biotechnology Letters
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    • v.20 no.3
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    • pp.295-301
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    • 1992
  • An alkaline protease producing microorganism was isolated from soil and identified as Streptomyces griseus HC-1141. The optimum pH and temperature for the purified enzyme activity were 8.0 and $60^{\circ}C$, respectively. The enzyme was relatively stable in the pH range of 7.0-9.0 and at the temperature below $60^{\circ}C$. The activity of purified enzyme was inhibited by $Hg^{2+}$, $Cu^{2+}$, $Zn^{2+}$, $Ba^{2+}$ and $Fe^{2+}$, whereas activated by $Mn^{2+}$ and $Ca^{2+}$. $\varepsilon$-Amino caproic acid, 2,4-dinitrophenol and iodine did not show inhibitory effect on the activity of alkaline protease, but p-chloromercuribenzoic acid, ethylendiaminetetraacetic acid showed inhibitory effect on the enzyme activity. These result suggested that the protease was metalloenzyme, and require a reactive SH group for the activity. The reaction of this enzyme follows typical Michaelis-Menten kinetics with the $K_m$ value of $2.229{\times}10^{-4}$M and the $V_{max}$ of $46.08 {\mu}$g/min for casein. The activation energy for the alkaline protease calculated by Arrhenius equation was 3.643 kcal/mol. This enzyme hydrolyzed casein more rapidly than the hemoglobin and egg albumin.

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Enzymatic Synthesis of Diacylglycerol Oil from Glyceryl Mono-oleate and Conjugated Linoleic Acid Using a Stirred-Batch Type Reactor (회분식 반응기를 이용한 Glyceryl Monooleate와 Conjugated Linoleic Acid로부터 효소적 반응을 통한 디글리세롤 유지의 합성)

  • Jeon, Mi-Sun;Lee, Ki-Teak
    • Food Science and Preservation
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    • v.16 no.2
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    • pp.246-252
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    • 2009
  • Diacylglycerol(DAG) was produced by enzymatic esterification of glyceryl mono-oleate(GMO) and conjugated linoleic acid(CLA) in a stirred-batch type reactor. The reaction was catalyzed by lipozyme RMIM(an immobilized lipase from Rizomucor miehei). DAG was isolated by a short-path distillation process and decolorized. DAG oil was composed of 87.3% DAG, 11.4% triacylglycerol(TAG), and 1.5% monoacylglycerol(MAG)(all w/w). Major fatty acids in DAG oil were oleic acid(54%), CLA(31.1%), and linoleic acid(7%). DAG oil iodine,and acid values were 108.8, 2.57, and 1, respectively. The DAG oil solid fat index(SFI) and thermograms were obtained using differential scanning calorimetry.

Photoluminescence of $Ga_2S_3$: Er Single Crystals ($Ga_2S_3$: Er 단결정의 Photoluminescence 특성 연구)

  • 진문석;김화택
    • Journal of the Korean Vacuum Society
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    • v.7 no.1
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    • pp.66-71
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    • 1998
  • Two kinds of $Ga_2S_3:Er$ (type A and type B) single crystals were grown by the chemical transport reaction method using iodine as a transport agent. The single crystals were crystallized into a monoclinic structure. The optical energy band gaps were found to 3.375 eV for the $Ga_2S_3:Er$ (type A) single crystal and 3.365 eV fir the $Ga_2S_3:Er$ (type B) single crystal at 13K. When the $Ga_2S_3:Er$ (type A and type B) single crystals were excited by the 325 nm-line of a Cd-He laser, Photoluminescence spectra of the $Ga_2S_3:Er$ (type A) single crystal exhibited blue emission band peaked at 444 nm and green and red emission bands peaked at 518 nm and 690 nm. Pgitikynubescebce soectra if the $Ga_2S_3:Er$ (typeB) single crystal showed green and red emission bands peaked at 513 nm and 695 nm. Sharp emission peaks in the two kinds if $Ga_2S_3:Er$ single crystal were observed near 525 nm, 553 nm, 664 nm, 812 nm, 986 nm, and 1540 nm and analysed as originating from the electron transitions between the energy levels of $Er^{3+}$ ion.

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