• Title/Summary/Keyword: KBr

Search Result 85, Processing Time 0.026 seconds

Separation of $PuO_2^{2+}$, $Pu^{4+}$ and $Pu^{3+}$ by Ion Chromatography (이온크로마토그래피에 의한 $PuO_2^{2+}$, $Pu^{4+}$$Pu^{3+}$의 분리)

  • Joe, Kih Soo;Kim, Jong Gu;Park, Yang Soon;Kim, Do Yang;Eom, Tae Yoon
    • Journal of the Korean Chemical Society
    • /
    • v.43 no.3
    • /
    • pp.280-285
    • /
    • 1999
  • Separation of plutonium species was studied by ion chromatography installed in a glove box for the determination of plutonium element. The plutonium species, $PuO_2^{2+},\; PC^{4+}\; and\; Pu^{3+}$, were stably separated on dynamically equilibrated cation exchanger using 1-octanesulfonate and ${\alpha}$-HiBA eluant after controlling the plutonium oxidation states with KI, $NaNO_2\;or=;KBrO_3$ based on the oxidation-reduction potentials. For the separation of plutonium from other matrix, $PuO_2^{2+}\; and\; Pu^{4+}$ were reduced to $Pu^{3+}$ with KI and $NaNO_2$ followed by cation exchange chromatography.

  • PDF

Korea Brassica Genome Project: Current Status and Prospective (배추 유전체열구의 현황과 전망)

  • Choi, Su-Ryun;Park, Jee-Yong;Park, Beom-Seok;Kim, Ho-Il;Lim, Yong-Pyo
    • Journal of Plant Biotechnology
    • /
    • v.33 no.3
    • /
    • pp.153-160
    • /
    • 2006
  • Brassica rape is an important species used as a vegetable, oil, and fodder worldwide. It is related phylogenically to Arabidopsis thaliana, which has already been fully sequenced as a model plant. The 'Multinational Brassica Genome Project (MBGP)'was launched by the international Brassica community with the aim of sequencing the whole genome of B. rapa in 2003 on account of its value and the fact that it has the smallest genome among the diploid Brassica. The genome study was carried out not only to know the structure of genome but also to understand the function and the evolution of the genes comprehensively. There are two mapping populations, over 1,000 molecular markers and a genetic map, 2 BAC libraries, physical map, a 22 cDHA libraries as suitable genomic materials for examining the genome of B. rapa ssp. pekinensis Chinese cabbage. As the first step for whole genome analysis, 220,000 BAC-end sequences of the KBrH and KBrB BAC library are achieved by cooperation of six countries. The results of BAC-end sequence analysis will provide a clue in understanding the structure of the genome of Brassica rapa by analyzing the gene sequence, annotation and abundant repetitive DHA. The second stage involves sequencing of the genetically mapped seed BACs and identifying the overlapping BACs for complete genome sequencing. Currently, the second stage is comprises of process genetic anchoring using communal populations and maps to identify more than 1,000 seed BACs based on a BAC-to-BAC strategy. For the initial sequencing, 629 seed BACs corresponding to the minimum tiling path onto Arabidopsis genome were selected and fully sequenced. These BACs are now anchoring to the genetic map using the development of SSR markers. This information will be useful for identifying near BAC clones with the seed BAC on a genome map. From the BAC sequences, it is revealed that the Brassica rapa genome has extensive triplication of the DNA segment coupled with variable gene losses and rearrangements within the segments. This article introduces the current status and prospective of Korea Brassica Genome Project and the bioinformatics tools possessed in each national team. In the near future, data of the genome will contribute to improving Brassicas for their economic use as well as in understanding the evolutional process.

Role of Some Benzohydrazide Derivatives as Corrosion Inhibitors for Carbon Steel in HCl Solution

  • Fouda, A.S.;Mohamed, M.T.;Soltan, M.R.
    • Journal of Electrochemical Science and Technology
    • /
    • v.4 no.2
    • /
    • pp.61-70
    • /
    • 2013
  • Corrosion inhibition of carbon steel in 2M HCl by some benzohydrazide derivatives (I-III) was studied using weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) techniques at $30^{\circ}C$. Polarization studies showed that all the investigated compounds are of mixed type inhibitors. Temperature studies revealed a decrease in efficiency with rise in temperature and corrosion activation energies increased in the presence of the hydrazide derivatives, probably implying that physical adsorption of cationic species may be responsible for the observed inhibition behavior. Electrochemical impedance studies showed that the presence of benzohydrazide derivatives decreases the double layer capacitance and increases the charge transfer resistance. The adsorption of these compounds on carbon steel surface was found to obey Temkin's adsorption isotherm. Synergistic effects increased the inhibition efficiency in the presence of halide additives namely KI and KBr. An inhibition mechanism was proposed in terms of strongly adsorption of inhibitor molecules on carbon steel surface.

Comparison of chemical and photochemical generation of hydrides in Se speciation study with HPLC-HG-ICPMS (HPLC-ICPMS를 이용한 셀레늄 화학종의 연구에서 화학적 및 광화학적 수소화물 발생법의 비교)

  • Ji, Hana;Pak, Yong-Nam
    • Analytical Science and Technology
    • /
    • v.25 no.6
    • /
    • pp.339-344
    • /
    • 2012
  • In this research, hydride generation in HPLC-ICPMS for the selenium speciation was investigated. Chemical and photochemical vapor generation techniques were compared for the effective generation of selenium vapour. $HBr/KBrO_3$ was used for the chemical reduction and a UV lamp was used for the photochemical reduction. It was found out that the photochemical reduction was more effective than the chemical reduction in all of selenium species studied. The optimum conditions for the generation of vapour are 0.4% KI, 2.5% $NaBH_4$, and 1.0 M HCl. The enhancement factor using a photochemical hydride generation was from 6.3 to 16.7 times for inorganic and organic selenium species.

Preparation of Nano AgBr Particles by Microemulsions (마이크로에멀젼을 이용한 AgBr 나노입자의 제조)

  • Jeong, Noh-Hee;Kim, Hong-Soo
    • Journal of the Korean Applied Science and Technology
    • /
    • v.21 no.1
    • /
    • pp.17-23
    • /
    • 2004
  • Silver bromide particles from 50 to 200${\AA}$ in diameter are prepared by mixing two microemulsions contaning the precursor salts $AgNO_3$ and KBr. The microemulsions are composed of AOT(bis(2-ethylhexyl) sodium sulfosuccinate), n-heptane and water. The particle diameters are measured on photomicrographs obtained by transmission electron microscopy. The size of the particles is generally larger than that of the water cores. The influence of both the concentration of precursor salts in the water cores of the microemulsoin and the size of these water cores on the size of the particles has been studied.

Effect of Enzymatically Hydrolyzed Vital Wheat Gluten on Dough Mixing and the Baking Properties of Wheat Flour Frozen Dough

  • Song, Kyung-Ah;Koh, Bong-Kyung
    • Food Science and Biotechnology
    • /
    • v.15 no.2
    • /
    • pp.173-176
    • /
    • 2006
  • The effect of enzymatically hydrolyzed vital wheat gluten (EHG) on dough mixing and the baking quality of wheat flour frozen dough was examined. Three different proteases, pepsin, trypsin, and chymotrypsin, were tested individually, sequentially paired, or in combination of all three enzymes. Addition of 1% EHG produced no observable effect on the mixing properties of wheat flour dough. However, addition of 2.5% pepsin-hydrolyzed gluten decreased the mixing tolerance of the wheat flour, and 1% trypsin-hydrolyzed gluten increased the loaf volume of both frozen and non-frozen dough. This finding suggests that trypsin-hydrolyzed vital wheat gluten may serve as a baking additive in replacement for $KBrO_3$ to improve frozen dough quality.

Antioxidative Activity and Protection of Oxidative Chromosomal Damage by Vegetables, Fruits Extract and Their Functional Liquid Formulation (야채 및 과일추출물의 항산화작용과 산화적 염색체손상에 대한 억제효과)

  • 이승철;허찬;이승현;김현표;허문영
    • YAKHAK HOEJI
    • /
    • v.48 no.2
    • /
    • pp.111-116
    • /
    • 2004
  • The ethanol extracts of mixed vegetables (Bioactive Vegetables, BV), mixed fruits (Bioactive Fruits, BF) and their liquid formulation (Chungpae Plus , CP) were evaluated for their antioxidative and antigenotoxic activities. They were shown to possess the significant free radical scavenging effect against 1,1-diphenyl-2-picryl hydrazine (DPPH) radical generation and were revealed to show the inhibitory effect of lipid peroxidation as measured by malondialdehyde (MDA) formation although the potencies were not higher than those of vitamin C. They did not possess any pro-oxidant effect on bleomycin-Fe(III) dependent DNA degradation, whereas vitamin C showed strong pro-oxidant effect. Furthermore, oral administration of BV and BF inhibited micronucleated reticulocyte (MNRET) formation of mouse peripheral blood induced by KBrO3 treatment in vivo. CP also showed significant inhibition under same experimental condition. Therefore, the liquid formulation (CP) containing BV and BF may be a useful natural antioxidative and antigenotoxic agent by scavenging free radicals, inhibition of lipid peroxidation and protecting chromosomal damage.

Comparison of methods for Determination of Aflatoxins in food Products (식품중 Aflatoxin 측정방법의 비교)

  • 김면희
    • Journal of Food Hygiene and Safety
    • /
    • v.11 no.2
    • /
    • pp.149-157
    • /
    • 1996
  • A procedure for the determination of Aflatoxins in food and grains which utilizes reversed phased liquid chromatographic (LC) analysis with postcolumn derivatization by an electrochemical cell and determination with a fluorescence detector has been evaluated. The LC mobile phase was water-acetonitrile-methanol (6+2+2) with 1mM KBr and 1 mM HNO3 which gave baseline separation for the four Aflatoxins (AfB1, AfB2, AfG1, AfG2). The electrochemical cell set at 7V, generated bromine and derivatized aflatoxins B1 and G1, The derivatives were detected by the fluorescence detector. The aflatoxins in naturally contaminated corn samples were isolated by three different cleanup procedures: the AOAC method I column(CB method), a rapid filtrate column (Romer's column), and an immunoaffinity column. The final extract were quantitated with fluordensitometric TLC and the LC postcolumn derivatization techniques. The results were quite similar, however the LC technique showed less interferences and could be automated. Samples of corn, raw peanuts, peanut butter and dried dates were also analyzed successfully with this procedure.

  • PDF

The characterization of ${In_2}{O_3}$ thin films prepared by activated reactive evaporation method (활성화 반응성 증착법에 의한 ${In_2}{O_3}$박막성장 및 특성)

  • 최명진;정진원;왕진석
    • Electrical & Electronic Materials
    • /
    • v.5 no.4
    • /
    • pp.400-405
    • /
    • 1992
  • 활성화 반응성 증착법으로 비저항 1.7*$10^{-3}$-8.0*$10^{-3}$ohm.cm, 전하운반자 농도 3.4*$10^{19}$-2.8*$10^{20}$$cm^{-3}$, 이동도 12-23$cm^{2}$/V.s, 금지대역 폭 3.35eV인 In/sib 2/ $O_{3}$박막을 KBr과 실리카 기판에 성장시켰다. 광투과율은 가시광선 영역에서 80% 이상을 나타냈으며 적외선 영역에서도 양호한 특성을 나타냈다. 박막성장시는 비정질 상태였으나 150.deg.C 이상에서 열처리했을 때 결정화현상이 관찰되었다.

  • PDF

Isolation and Characterization of Lipophorin from Lymantria dispar L. (매미나방(Lymantria dispar L.)의 Lipophorin의 정제 및 특성)

  • 류재구;김학열
    • The Korean Journal of Zoology
    • /
    • v.34 no.1
    • /
    • pp.1-7
    • /
    • 1991
  • Lipophorin of Lymuntrn'adispor L. has been purified by KBr density gradient ultracentrifugation. The properties and synthetic site of lipophorin and quantitative change of lipophorin during development have been determined using electrophoresis and immunological analysis. Lipophorin is composed of ho subunits. apo-Lpl (230.000), ago-Lpll (49,000). ann contains carbohydrates and lipids. Anti-lipophorin showed positive reactions with fat body extract and ovary extract but not with gut extract. The concentration of lipophorin in hemolymph showed gradual decrease during larval and pupal stages. Also. fat body released lipophorin into medium. Immunological test showed some partial identity between lipophorin of Lymantpia dispar and hemolymph proteins (probably lipophorin) of Hyphontria cuneo and Galleria metlonefla.

  • PDF