• Title/Summary/Keyword: metal salt

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Electrochemical Properties of Carbonized Phenol Resin (탄화된 페놀레진의 전기화학적 성질)

  • 김한주;박종은;홍지숙;류부형;박수길
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.629-632
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    • 1999
  • For replacing Li metal ai Lithium ton Bakery(LIB) system. we used carbon powder material which prepared by pyrolysis of phenol resin as starting material. It became amorphous carbon by pyrolysis through it\`s self condensation by thermal treatment. Amorphous carbon can be doped with Li intercalation and deintercalation because it has wide interlayer. however it has a problem with structural destroy causing weak carbon-carbon bond. So. we used ZnCl$_2$ as the pore-forming agent. This inorganic salt used together with the resin serves not only as the pore-forming agent to form open pores, which grow Into a three-dimensional network structure in the cured material, foul also as the microstructure-controlling agent to form a loose structure dope with bulky dopants. We analyzed SEM in order to find to different of structure. and can calculate distance of interlayer. CV test showed oxidation and reduction

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Characteristics of Reduced Metal from Spent Oxide Fuel by Lithium

  • Kim Ik-Soo;Seo Chung-Seok;Shin Hee-Sung;Hwang Yong-Soo;Park Seong-Won
    • Nuclear Engineering and Technology
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    • v.35 no.4
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    • pp.309-317
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    • 2003
  • The mass balance of the unit processes of the Advanced spent fuel Conditioning Process was calculated to obtain basic information. Based on this mass balance, the changes in decay heat and radioactivity of the spent fuel due to the metallization in the high temperature molten salt system were estimated. The decay heat and the radioactivity were calculated by using the ORIGEN2 computer code, and the result showed that the decay heat and the radioactivity of the metallized spent fuel ingot were $24.27\%\;and\;24.24\%$, respectively, compared to those of oxide spent fuel.

A Study on water-splitting characteristics of bipolar membranes for acid/base generation (산/염기 제조를 위한 바이폴라막의 물분해 특성 연구)

  • 강문성;문승현;이재석
    • Proceedings of the Membrane Society of Korea Conference
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    • 1998.10a
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    • pp.75-78
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    • 1998
  • 1. Introduction : The clean technology using ion exchange membranes have drawn attention increasingly with advancement of the membrane synthesis. Ion exchange membranes have been used for diffusion dialysis, electrodialysis, electrodialytic water splitting and electrodeionization. Bipolar membranes(BPM), consisting of a cation exchange layer and an an_ion exchange layer, can convert a salt to an acid and a base without chemical addition. Using the bipolar membrane, a large quantity of industrial wastes containing salts can be reprocessed to generate acids and bases. Recent development of high performance bipolar membranes enables to further expand the potential use of electrodialysis in the chemical industry. The water-splitting mechanism in the bipolar membrane, however, is a controversial subject yet. In this study bipolar membranes were prepared using commercial ion exchange membranes and hydrophilic polymer as a binder to investigate the effects of the interface hydrophilicity on water-splitting efficiency. In addition, the water splitting mechanism by a metal catalyst was discussed.

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Characteristics of bluish Purple Pigment Produced by Streptomyces californicus KS-89 (Streptomyces californicus KS-89 에 의하여 생산되는 청자색 색소의 특성)

  • 류병호;지영애;이병호;박법규;박우열
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.19 no.3
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    • pp.263-269
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    • 1990
  • Aqueous solution pigment produced by Steptomyces californicus KS-89 showed a vivid bluish purple pigment and purified by silica gel column chromatography. The pigment indicated a deep purple color zone by the C. I. E chromatic diagram and showed UV absorption maxima at 575nm. The color intensity in aqueous solution was fairly stable in the ranges of pH5-8 and was not affected by UV light however sometimes it had faded slightly by the heat. It was possible to prevent significantly by the addition of metal salt. Especially this pigment has no mutagenicity and antitumor activity and it appears to be devoid of antibiotic activity.

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Attempts on the Preparation of Lithium Trialkoxyborohydrides. Stability and Stereoselective Reduction of Cyclic Ketones

  • Cha, Jin-Soon;Kim, Jin-Euog;Lee, Jae-Cheol;Yoon, Mal-Sook
    • Bulletin of the Korean Chemical Society
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    • v.7 no.1
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    • pp.66-69
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    • 1986
  • The reaction of potassium trialkoxyborohydrides of varying steric requirements with lithium chloride in tetrahydrofuran(THF) was examined in detail to establish the generality of this synthesis of the corresponding lithium trialkoxyborohydrides. The metal ion exchange reaction between potassium triisopropoxyborohydride and lithium chloride in THF proceeded instantly at room temperature and the corresponding lithium salt was very stable toward disproportionation. However, for R = s-Bu, t-Bu and 2-methylcyclohexyl, with increasing steric requirement, the lithium derivatives were unstable and thus dissociated into $(RO)BH_3^-\;and\; (RO)_4B^-$. The stereoselectivity of lithium triisopropoxyborohydride(LIPBH) in the reduction of representative cyclic ketones was examined and compared with that of the potassium derivative.

Different Adsorption Behavior of Rare Earth and Metallic Ion Complexes on Langmuir Monolayers Probed by Sum-Frequency Generation Spectroscopy

  • Sung, Woongmo;Vaknin, David;Kim, Doseok
    • Journal of the Optical Society of Korea
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    • v.17 no.1
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    • pp.10-15
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    • 2013
  • Adsorption behavior of counterions under a Langmuir monolayer was investigated by sum-frequency generation (SFG) spectroscopy. By comparing SFG spectra of arachidic acid (AA) Langmuir monolayer/water interface with and without added salt, it was found that the simple trivalent cation $La^{3+}$ adsorbed on AA monolayer only when the carboxylic headgroups are charged (deprotonated), implying that counterion adsorption is induced by Coulomb interaction. On the other hand, metal hydroxide complex $Fe(OH)_3$ adsorbed even on a charge-neutral AA monolayer, indicating that the adsorption of iron hydroxide is due to chemical interaction such as covalent or hydrogen bonding to the headgroup of the molecules at the monolayer.

U/RE Recovery Using Large-Scale LCC Electrowinning System

  • Kim, Si Hyung;Shim, Joon-Bo;Jang, Junhyuk;Kwon, Sang-Woon;Lee, Young Sang;Kwon, Youngwoo;Kim, Gha-Young;Lee, Sung-Jai
    • Proceedings of the Korean Radioactive Waste Society Conference
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    • 2018.05a
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    • pp.53-54
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    • 2018
  • U/RE was electrochemically recovered to LCC at $50mA/cm^2$ from LiCl-KCl salt containing $0.5wt%UCl_3$, $0.22wt%NdCl_3$, 0.15wt%$CeCl_3$ and $0.07wt%LaCl_3$. The Cd in the LCC deposit was removed during the distillation using Cd distiller. U/RE product of 107g obtained from the distiller was installed to TG and then heated to $1200^{\circ}C$ to be consolidated. Dense U/RE metal ingot was not acquired through the consolidation process because U/RE product had been partially already oxidized during the distillation process.

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Assessment Techniques of Heavy Metal Bioavailability in Soil - A critical Review (토양 중 중금속 생물유효도 평가방법 - 총설)

  • Kim, Kwon-Rae;Owens, Gary;Naidu, Ravi;Kim, Kye-Hoon
    • Korean Journal of Soil Science and Fertilizer
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    • v.40 no.4
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    • pp.311-325
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    • 2007
  • The concept of metal bioavailability, rather than total metal in soils, is increasingly becoming important for a thorough understanding of risk assessment and remediation. This is because bioavailable metals generally represented by the labile or soluble metal components existing as either free ions or soluble complexed ions are likely to be accessible to receptor organismsrather than heavy metals tightly bound on soil surface. Consequently, many researchers have investigated the bioavailability of metals in both soil and solution phases together with the key soil properties influencing bioavailability. In order to study bioavailability changes various techniques have been developed including chemical based extraction (weak salt solution extraction, chelate extraction, etc.) and speciation of metals using devices such as ion selective electrode (ISE) and diffusive gradient in the thin film (DGT). Changes in soil metal bioavailability typically occur through adsorption/desorption reactions of metal ions exchanged between soil solution and soil binding sites in response to changes in environment factors such as soil pH, organic matter (OM), dissolved organic carbon (DOC), low-molecular weight organic acids (LMWOAs), and index cations. Increasesin soil pH result in decreases in metal bioavailability through adsorption of metal ions on deprotonated binding sites. Organic matter may also decrease metal bioavailability by providing more negatively charged binding sites, and metal bioavailability can also be decreases as concentrations of DOC and LMWOAs increase as these both form strong chelate complexeswith metal ions in soil solution. The interaction of metal ions with these soil properties also varies depending on the soil and metal type.

Characteristics of Lithium Metal Secondary Battery Using PAN Gel-electrolyte Mixed with TiO2 Ceramic Filler (TiO2 Ceramic Filler가 혼합된 젤상의 PAN 고분자 전해질을 이용한 리튬금속 이차전지의 특성)

  • Lim, Hyo-Sung;Kim, Hyung-Sun;Cho, Byung-Won;Lee, Tae-Hee
    • Journal of the Korean Electrochemical Society
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    • v.5 no.3
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    • pp.106-110
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    • 2002
  • Gel-type polyacrylonitrile(PAN) polymer electrolytes have been prepared using ethylene carbonate(EC), propylene carbonate(PC) and dimethyl carbonate(DMC) plasticizer, $LiPF_6$ salt and $TiO_2$ ceramic filler. Electrochemical properties, such as electrochemical stability, ionic conductivity and compatibility with lithium metal and mechanical properly of polymer electrolytes were investigated. Charge/discharge performance of lithium secondary battery using these polymer electrolytes were investigated. The maximum load that the polymer electrolyte resists increased about two times as a result of adding $TiO_2$ in the polymer electrolyte containing EC and PC. Polymer electrolyte containing EC, PC and $TiO_2$ also showed ionic conductivity of $2\times10^{-3} S/cm$ at room temperature and electrochemical stability window up to 와 4.5V. Polymer electrolyte containing EC, PC, and $TiO_2$ showed the most stable interfacial resistance of $130\Omega$ during 20 days in the impedance spectra of the cells which were constructed by lithium metals as electrodes. Lithium metal secondary battery which employed $LiCoO_2$ cathode, lithium metal anode and $TiO_2$-dispersed polymer electrolyte showed $90\%$ of charge/discharge efficiency at the 1C rate of discharge.

A Study on the Optimal Design and Performance Analysis of the Solid-Gas Chemical Heat Transformer (고-기 화학열변환기의 최적설계 및 성능해석에 관한 연구)

  • Choi, S.H.;Lee, S.I.;Baek, I.H.;Choi, I.S.
    • Applied Chemistry for Engineering
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    • v.8 no.5
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    • pp.729-736
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    • 1997
  • For the recovery of industrial waste heat, a chemical heat transformer based on the reversible reaction between metal chlorides and ammonia gas was designed and a pilot scale unit of 1 kW-1hr was developed. A static calculation, which determined the amount of reacting materials and operating condition of system, and dynamic simulations were performed for the optimal design. The temperature and output power of generator in the system were varying with the amount of salt and heat exchange area. Optimum conditions such as the amount of salt-graphite, apparent density and size of mechanical unit were determined by the dynamic simulation for the system. According to the operating cycle of 4 stages, experimental results of temperature and output power were well agreed with the simulation values. This chemical heat transformer is turned out to be a very promising system for recovery of industrial waste heat because of its effective feature of lifting temperature.

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