• Title/Summary/Keyword: lron

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왕겨의 화학원료재로서의 이용

  • 남궁식;김창열;유의연
    • Proceedings of the Korean Society for Applied Microbiology Conference
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    • 1974.06a
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    • pp.123.1-123
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    • 1974
  • 본보에 있어서는 착화성과 연소성우가 큰 도시윤정편 담연란의 제조를 시도하여 그 기초 시험연구를 통하여 얻은 결과를 보고한다. 일본에 있어서는 예컨데 Mifuji Lron works ltdo가 연구한 왕겨 탄화장치(MAC PLAT : 일본특허)가 책용화 되고 있으며 (1971) 금업적 수익성이 좋은 편은 못되나 두탄, 열담의 열연탄요, 제양용탈발제, 야금용환원제, 농업용토질개양제 기타 많은 용도가 개발되고 있다. 특히 경제성을 확보하기 위하여 독자적인 왕겨 탄화 plant의 process설계와 탄화 왕겨의 활용방안에 관한 연구가 종합적으로 행하고저 한다.

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The Effect of Carbon on the Hot Corrosion of lron by Sulfur Containing Environment. (철의 고온 황화부식에 미치는 탄소의 영향)

  • 최성필;강성군;백영남
    • Journal of the Korean institute of surface engineering
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    • v.21 no.2
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    • pp.53-67
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    • 1988
  • The high temperature corrosion of Fe-C alloys were studied at I atm SO gas in the temperature range 500~80$0^{\circ}C$ by means of a thermogravimetric analysis. The Na2SO4 induced high tempwrature corrosion rate was also measured at atm O2 gas under above the temperature renge. The reaction products were identified with the aid of X-ray diffraction technique, and micostruction of the alloy/scale interface was observed with a optical microscope and SEM. The experimental results were disussed by the themodeynamic calcutions. Under above the experimental condition. the reaction rates decrbon with increasing carbon content. The transfer of Fe ion was limited by a residue of carbon precipitated at alloy scale interface due to the oxidation of Fe-C alloys at alloy surface. The effect of cold working on reaction rate was different between the Fe containing low carbon and Fe-C Alloy containing carbon above 0,73 wt%. In a cold worked iron containing low carbon content, the crystallization of metal surface leads to the poor adherence between the alloy and the cavity formed between the alloy and scale. The outward diffusion of ion through the scale is estimated to be hindered by the cavity formed between the scale, consequently decreasing reaction rate. In the case Fe-C containing carbon above 0.73 Wt% alloy, the reaction rate was little affected by cold working, because the effect of content on reaction rats is greater than the effect of cold working.

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Conservation of artifacts excavated from Imdang, Kyǒngsan Province-Metals and Lacquerware (경산시 임당유적 출토 유물 보존처리-금속 및 칠기유물을 중심으로)

  • Yu, Jae-Eun;Shin, Ui-Kyoung;Hwang, Jin-Ju;Goh, Dong-Ha
    • 보존과학연구
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    • s.19
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    • pp.109-132
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    • 1998
  • According to excavation of Imdang site, these sites were excavated place to a various of sites from Early lron period to the Koryo Kingdom. Artifacts to be conserved were excavated from A, D and E district. Metal artifacts were excavated from D and E district and lacquer ware artifacts were excavated from Adistrict. Metal artifacts including lacquer ware iron sword, imitative bronze mirror, Osujen and bronze artifact with letter and so on. Bronze artifacts were covered with soil and rust and performed consolidation after passivation treatment with Benzotriazole solution. Also, iron artifacts performed desalting treatment with 0.1M sesquicarbonate solution. After desalinization, adhesive of these artifacts were processed with Araldite(rapid type) after consolidation with20%∼30% NAD-10 solution. Lacquer ware artifacts remained fragments of lacquer to be all corroded and soiled. Therefore these artifacts retained its original form. Fragments of lacquer joined with Caparol 1%∼3% solution and the soil of relics coated with PSNY 3%∼6% solution. There were many kinds of lacquer were. Lacquer ware artifacts presumed to a string instrument that provide important clues for lacquer ware research. As for lacquer fragments inquire, paints grain size were $2∼5\mum$ and conformed to vanished three times.

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Molecular cloning and expression analysis of a ferritin H subunit from rock bream, Oplegnathus fasciatus (돌돔 ferritin H 유전자의 클로닝과 발현 분석)

  • Kwon, Mun-Gyeong;Jeong, Ji-Min;Kim, Ju-Won;Park, Chan-Il
    • Journal of fish pathology
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    • v.26 no.3
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    • pp.295-301
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    • 2013
  • Ferritin is an evolutionarily conserved protein that plays an important role in iron storage and detoxification. In this study, the gene encoding a ferritin H subunit homologue (RbFH) was cloned from rock bream (Oplegnathus fasciatus) and analyzed at the expression. The full-length ferritin H cDNA was 1162 bp long and contained an open reading frame (ORF) of 531 bp that encoded 177 amino acid residues with a predicted molecular mass of 20.8 kDa. The 5' UTR was 297 bp in length, and the 3' UTR 298 bp, and preceded by a 5'-untranslated region that contains a putative Iron Regulatory Element (IRE). The deduced amino acid sequence of RbFH shares extensive sequence identities with the H ferritins of a number of fish species and contains the ferroxidase center that is preserved in ferritin H subunits. Examination of tissue specific expression indicated that RbFH expression was most abundant in PBLs, RBC, liver and muscle.

The Electrode Characteristics of the Sintered AB5-type Metal Hydrogen Storage Alloy for Ni-MH Secondary Battery (Ni-MH 2차전지용 AB5계 수소저장합금의 소결에 따른 전극 특성)

  • Chang, Sang-Min;Park, Won;Choi, Seung-Jun;Noh, Hak;Choi, Jeon;Park, Choong-Nyeon
    • Transactions of the Korean hydrogen and new energy society
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    • v.7 no.2
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    • pp.157-164
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    • 1996
  • The AB5-type metal hydride electrodes using $(LM)Ni_{4.49}Co_{0.1}Mn_{0.205}Al_{0.205}$(LM : Lanthaniumrich Mischmetal) alloy powders(${\leq}200$mesh) which were coated with 25wt% copper in an acidic bath were prepared with or without addition of 10wt% PTFE as a binder. Prior to electrochemical measurements, the electrodes were sintered at $40^{\circ}C$ for 1 and 2hrs in vacuum with Mm(mischmetal) and sponge type Ti getters. The properties such as maximum capacity, cycle life and mechanical strength of the negative electrode have been investigated. The surface analysis of the electrode was also obtained before and after charge-discharge cycling using scanning electron microscope(SEM). From the observations of electrochemical behavior, it was found that the sintered electrode shows a lower maximum discharge capacity compared with non-sintered electrode but it shows a better cycle life. For the both electrodes with or without addition of PTFE binder, the values of mechanical strength were obtained, and their values increased with increasing sintering time. However, there is little difference of discharge capacity for both electrodes.

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Optical Characteristics of Iron Silicide Films Prepared by Plasma CVD (Plasma CVD에 의해 제조된 Iron Silicide 박막의 광학적 특성)

  • Kim, Kyung-soo;Yoon, Yong-soo;Jung, Il-Hyun
    • Applied Chemistry for Engineering
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    • v.10 no.3
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    • pp.343-348
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    • 1999
  • The iron silicide films were prepared by chemical vapor deposition method using rf-plasma in variations of substrate temperature. rf-power, and ratio of $SiH_4$ and Fe-precursor. While iron silicide films are generally grown by ion beam synthesis (IBS) method of multi-step process, it is confirmed that iron silicide or $\beta$-phase consolidated $Fe_aSi_bC_cH_d$ was formed by one-step process in this study. The characteristics of films is variable because the different amounts of carbon and hydrogen was involved in the films as a function of dilute ratio of Fe-precursors and silane. It was shown that the different characteristics of films in carbon and hydrogen following the ratio of Fe-precursor and silane. The optical gap energy of films fabricated according to substrate temperature was invariant because active site brought in desorption of hydrogen was limiled. When rf-power was above 240 watt, the optical gap energy turned out to have high values because of dangling bonds increased by etching.

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Structural, Magnetic, and Magneto-Optic Properties of Nonstoichiometric Bismuth-Substituted Yttrium lron Gamet Films Prepared by Pyrolysis (열분해법에 의해 제조한 비화학양론조성을 갖는 비스머스 치환 이트리움-철-가네트 박막의 구조적, 자기적 및 자기광학적 특성)

  • Jae-Kyong Cho
    • Journal of the Korean Magnetics Society
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    • v.4 no.1
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    • pp.39-43
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    • 1994
  • Polycrystalline nonstoichiometric bismuth-substituted yttrium iron garnet films with cation ratios of Bi:Y:Fe=1.5+u:1.5:5 and Bi:Y:Fe=1.5:1.5+v:5, where $-0.7{\leq}u{\leq}1.0$ and $-0.7{\leq}v{\leq}1.3$, have been prepared by pyrolysis. The crystal phases formed in these films at various temperatures have been analyzed by high power x-ray diffractometry (XRD). The saturation ma- gnetization, the Curie temperatures, and the Faraday rotation at the wavelength of 633 nm have been measured as a function of u and v. The XRD studies indicated that the bismuth and yttrium depleted (u < 0 and v < 0) films consisted of the mixed phases of garnet and impunity. While in the bismuth and ytrium overdosed films, no impurity lines were observed over a wide composition range of $0{\leq}u{\leq}0.5$ and $0{\leq}v{\leq}0.7$. The observed magnetic and magneto-optic data of these overdosed films, however, could only be reasonably explained by assuming the presence of samll amount of spurious phases, not detectable by the XRD.

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The Responses of Particulate Phosphorus Exposed to the Fresh Water in Marine Sediment (담수화로 인한 퇴적물 내 입자성 인의 거동에 관한 실험적 연구)

  • Ji, Kwang-Hee;Jeong, Yong-Hoon;Kim, Hyun-Soo;Yang, Jae-Sam
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.12 no.2
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    • pp.84-90
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    • 2009
  • We incubated marine columnar sediments at $25^{\circ}C$ for 230 days to simulate the responses of phosphorus in the sediment which was exposed to freshwater. The incubation was composed of three different treatments (FW: freshwater, FWA: freshwater under anoxic condition, and SW: seawater as a Control). Six particulate fractions of phosphorus in sediment were obtained through sequential extraction and, for comparison, phosphate concentrations in porewater and superlying water were also determined. After the incubation, evidently higher concentrations of phosphate were found in FW and FWA compared to SW. Mass extinction of living organisms in marine sediment from freshwater shock and consequent decay of their corps probably contributed such high phosphate spike in the overlying water. Higher concentrations of BD-P(lron-bound P) were found in FW compared to SW. After exposure to the freshwater, we could determine that penetration depth of dissolved oxygen in marine sediment will be deeper. A result of increases of ferrous compounds in freshwater where contained less sulfide has been obtained. Because of these phenomena, BD-P was increased in FW. On the contrary, BD-P was decreased in FWA since poor dissolved oxygen concentration. In FWA, total amount of Leachable P(SUM of LOP) has been remarkably increased through the experiment, which strongly suggested the easy conversion of the leachable P into reactive P. This experiment has shown that most of diverse P species in marine sediment were leachable under freshwater and low oxygen condition. Therefore reclamation of natural tidalfalt and consequent freshwater introduction seems to trigger the conversion of diverse P-species to leachable P in the marine sediments, which will exert high benthic load of phosphate to the overlying water.

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