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        검색결과 83

        41.
        2013.04 구독 인증기관 무료, 개인회원 유료
        심해저 망간단괴의 탐사규칙에 따른 탐사계약이 오는 2016년 만료되는 국가가 많으므로 탐사규칙에 이은 개발규칙의 준비가 본격화 되고 있다. 본 논문에서는 심해저 망간단괴 개발규칙의 핵심쟁점으로 예상되는 사안들을 살펴보고 그에 대한 분석 및 향후 연구과제를 도출한다. 망간단괴 개발규칙에 있어서 가장 핵심이 될 것으로 예상되는 쟁점은 계약의 유형, 면허의 종류, 재정체계 등이다. 계약의 종류는 프로젝트에 대한 정부의 통제가 가능한 서비스계약과, 운영자의..
        3,000원
        43.
        2012.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        무기안료는 인체에 대한 안정성과 다른 소재와의 상용성이 우수하며, 미적 특성을 감미하기 위한 화장품, 인쇄잉크, 페인트, 건설자재 등 다양한 분야에서 관심 받고 있다. 본 논문에서는 망간과 철이 도핑된 이산화티탄 안료를 합성하기 위하여 수열합성법을 이용하였다. 공정 변수로는 망간 전구체의 양, 철 전구체의 양 및 하소온도 등을 변화시켰다. 제조된 안료의 최적 조건은 망간 전구체의 양이 1.0wt%, 철 전구체의 양이 1.5wt% 그리고 하소온도 550℃일 때였다. 제조된 안료는 XRD, EDS, FE-SEM, Spectrophotometer, UV-Vis Spectrometer 등으로 분석 하였다.
        4,000원
        44.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Mass production-capable powder was synthesized for use as cathode material in state-of-the-art lithium-ion batteries. These batteries are main powder sources for high tech-end digital electronic equipments and electric vehicles in the near future and they must possess high specific capacity and durable charge-discharge characteristics. Amorphous silicone was quite superior to crystalline one as starting material to fabricate silicone oxide with high reactivity between precursors of sol-gel type reaction intermediates. The amorphous silicone starting material also has beneficial effect of efficiently controlling secondary phases, most notably . Lastly, carbon was coated on powders by using sucrose to afford some improved electrical conductivity. The carbon-coated cathode material was further characterized using SEM, XRD, and galvanostatic charge/discharge test method for morphological and electrochemical examinations. Coin cell was subject to 1.5-4.8 V at C/20, where 74 mAh/g was observed during primary discharge cycle.
        4,000원
        47.
        2006.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        담양 지역의 음용 지하수 중에 형성된 망간 스케일의 지구화학적 특성을 규명하고자 하였다. 망간 스케일은 MnO 및 SiO2로 구성되어 있고, MnO의 함량은 56.61wt.%에서 68.69wt.%, 그리고 SiO2 함량은 1.56wt.%에서10.45wt.%로 나타난다. 망간 스케일 중의 Ba와 Mo 함량은 지하수 심도가 증가할수록 증가하여 나타나고 Zn과 Pb는심도가 증가할수록 감소한다. 망간 스케일을 x-선 회절 분석을 한 결과 birnessite, 석영 및 장석이 분석되었다. IR 분석에서 망간 스케일은 OH, H2O 그리고 birnessite에 의한 흡수 밴드가 관찰된다. SEM 및 EDS 분석에서 망간 스케일은 포도송이 구조, 과립 구조, 구상 구조 및 속이 빈 straw 구조로 되어 있는 것이 관찰된다. 이들 구조들은 고농도의 망간함량에 의해 단순히 과포화로 침전되었을 것으로 생각되며, 혹은 Lepthothrix discophora에 의해 미생물적으로 침전되었을 것으로 생각된다. 이들 구조들의 표면을 EDS로 분석한 결과 Mn의 원자(atomic) 퍼센트가 28에서 44범위로 나타나고 Si, K, Na, Ca, Cl, Cu, Zn 및 Ba 등이 검출된다.
        4,800원
        50.
        2001.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The effects of mechanical alloying conditions on the formation of Mn-sulfide powders were analyzed. Impeller rotating speed, lubricant coating and added amounts of process control agent(stearic acid) were selected as a process control factor. MnS compounds are synthesized in 3 hours by mechanical alloying at the alternative milling condition. Discontinuous rotating speed of 1200rpm for 4 minutes and 1000rpm for 1 minute shows more effects on the compound formation of MnS. After coating of lubricant on the wall, elementary Mn and sulfur were partially remained by mechanical alloying. The friction effects of the wall and grinding media on the powders are significantly important to form the compound of MnS.
        4,000원
        52.
        2000.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        For decompose carbon dioxide, manganese oxide was synthesized with 0.25M-MnSO4·nH2O and 0.5M-NaOH by coprecipitation. We made magnetite deoxidized manganese oxide by hydrogen reduction for 1hour at 330℃. We investigated characteristics of catalyst, hydrogen reduction degree and decomposition rate of carbon dioxide. The structure of the hausmannite certified spinel type. The specific surface area of synthesized hausmannite and deoxidized hausmannite were 22.36m2/g, 33.56m2/g respectively. The decomposition rate of CO2 of deoxidized hausmannite was 57%.
        4,000원
        53.
        1998.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        재충전이 가능한 Li/PEO-LiClO4-PC/LIMn2O4구조의 전고상 전지를 제작하였다. LIMn2O4박막은 RF 마그네트론 스퍼터링 법으로 제작하였으며, 750˚C 부근에서의 급속열처리를 통하여 스피넬 상으로 결정화시킬 수 있었다. 상온 충.방전 시험을 행한 결과, 평균 전압 4V(vs. Li)의 평탄한 방전 전압과 우수한 재충전 능력을 나타내었다.
        4,000원
        55.
        1995.06 구독 인증기관·개인회원 무료
        Liquid phase sintering of 90W-6Ni-4Mn alloy has been investigated as functions of sintering atmosphere, heating rate, and reduction temperature. The present work accounts for the thermodynamic oxidatiodreduction reactions of constituent powders of W, Ni and Mn. By discounting these reactions, the previous investigations would obtain only the alloy with large pores and the lowered relative sintered density, by the liquid phase sintering under a dry hydrogen atmosphere. the sintering cycle consisted of a rapid heating to reduction temperatures under high purity nitrogen atmosphere, and holding for 4 hours and sintering at for 1 hour under a dry hydrogen gas. The relative density of the sintered alloy increased with increasing heating rate. As the reduction temperature increased, the relative density increased to the lm theotical density at the duction temture above . The mimsturcatre of sintered alloys has been analysed by a scanning election microscope. The sintered density was compared with those obtained from the other investigators. It was found that the reduction results in the lowered densification of 90W-6Ni-4Mn alloy. This is caused by the fact that reducing reactions of W and Ni oxides contained in W an Ni powders concomitantly leads to oxidizing reaction of Mn powder the oxidized Mn is hardly reduced at sintering temperature and thereby remains large pores in the alloy. It is concluded that the W-Ni-Mn alloy with full density can be obtained by the precise control of atmosphere, heating rate, and sintering temperature.
        56.
        1992.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        시약급 망간염과 폐건전지에서 회수한 망간염 수용액을 전해액으로 사용하고, 0.2% 저탄소 연강을 가용성 양극으로, SUS 304 스테인레스 강을 음극으로 하여 전기분해 법에 의해 생성된 망간 페라이트의 화학조성 및 열적, 자기적 성질을 조사한 결과 다음과 같다. MnxFe3-xO4(O<X<3) 산화물은 X=1에서 스핀넬형 망간 페라이트가 생성되었고, 망간함량이 증가할수록 200˚C까지는 중량감소량이 직선적으로 증가하였다. 망간함량과 가열온도가 증가할수록 보자력이 감소하고 포화자화도 감소하는 경향을 보였다. 시약급 염화망간염을 전해액으로하여 생성시킨 망간 페라이트가 황산망간 및 폐건전지에서 회수한 망간염을 전해액으로 사용하여 제조한 망간 페라이트 보다 포화자화값이 높았다. 200˚C, 300˚C로 가열하였을 때, 폐건전지에서 침출한 황산망간염을 전해액으로 하여 생성시킨 망간 페라이트가 시약급 황산망간염을 전해액으로 하여 생성시킨 망간 페라이트 보다 포화자화와 잔류자화값이 높았다. 생성된 입도는 모두 구형이었고, 시약급 황산망간염을 전해액으로 하여 생성시킨 망간 페라이트에서는 0.1μm, 폐건전지에서 침출한 황산망간염을 전해액으로 하여 생성시킨 망간 페라이트에서는 0.5μm 범위의 미립자로 생성되었다.
        4,000원
        57.
        1990.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The major product of wolframite series in Korea are wolframite and ferberite. In Cheolam silver deposits, however, huebnerite is occurred. The formation conditions of huebnerite and ferberite are similar, but that of huebnerite is higher Mn/Fe ratio and neutral or alkaline than ferberite. Based on E.P.M.A. data, chemical composition of the huebnerite from Cheolam silver deposits is (Mn_(0.89) Fe_(0.11))WO₄. The measured cell dimensions of the huebnerite is a_o=4.825Å, b_o= 5.755Å, c)o=4.997Å, the angle β=91.03° To compared with huebnerite will be occurred in the other districts, reflectivity and absolute hardness(VHN) were measured and described.
        4,000원
        58.
        2020.11 KCI 등재 서비스 종료(열람 제한)
        This study investigated the distributional pattern of meiobenthos associated with future deep-sea mining in the Korea Deep Ocean Study area present in the Clarion-Clipperton Fracture Zone (CCFZ) located in the southeastern part of the North Pacific Ocean. Standing stocks of meiobenthos were investigated in benthic impact experiment sites (BIS) and Korea Institute of Ocean Science & Technology long-term monitoring (KOMO) sites during the 2008-2014 annual field survey. A total of 14 taxa of meiobenthos were identified. Nematodes were the most abundant taxon (60-86%). Harpacticoid copepods (5-26%) and benthic foraminifera (1-12%) were also dominant at all sites. The total meiobenthic densities varied from 4 to 150 ind./10 cm2. The mean value of total meiobenthic abundance was higher at BIS than at KOMO sites, but there was no significant difference between the two sites. The mean values of the number of taxa and biomass at BIS and KOMO sites were similar. The mean abundance of nematodes that were the most dominant taxa was also higher at BIS than at KOMO sites. The standing stocks in our study sites were relatively lower than those previously reported at other CCFZ sites. These results seem to reflect a low organic concentration in the study area.
        59.
        2020.08 KCI 등재 서비스 종료(열람 제한)
        Zeolite material having XRD peaks of Na-A zeolite in the 2θ range of 7.18 to 34.18 can be synthesized from the waste catalyst using a fusion/hydrothermal method. The adsorption rate of Mn ions by a commercial Na-A zeolite and the synthesized zeolitic material increased as the adsorption temperature increased in the range of 10 ~ 40℃. The adsorption of Mn ion were very rapid in the first 30 min and then reached to the equilibrium state after approximately 60 min. The adsorption kinetics of Mn ions by the commercial Na-A zeolite and the zeolitic material were found to be well fitted to the pseudo-2nd order kinetic model. Equilibrium data by the commercial Na-A zeolite and the zeolitic material fit the Langmuir, Koble-Corrigan, and Redlich-Peterson isotherm models well rather than Freundlich isotherm model. The removal capacity of the Mn ions by the commercial Na-A zeolite and the zeolitic material obtained from the Langmuir model was 135.2 mg/g and 128.9 mg/g at 30℃, respectively. The adsorption capacity of Mn ions by the synthesized zeolitic material was almost similar to that of commercial Na-A zeolite. The synthesized zeolitic material could be applied as an economically feasible commercial adsorbent.
        60.
        2020.01 KCI 등재 서비스 종료(열람 제한)
        The effects of liquid potassium permanganate (KMnO4) on the litter quality of poultry were investigated. Two-hundred -forty 0-day-old broiler chickens (Arbor Acres) were randomly assigned to two treatments with four replicated pens of 30 chickens each. Treatment liquid KMnO4 at a rate of 50 g of liquid KMnO4/kg of poultry litter was sprayed onto the litter surface using a small hand pump; others served as a control that was applied without liquid KMnO4 additions. Compared with controls, the treatment liquid KMnO4 showed no differences in pH, total nitrogen and ammonia concentration. It was concluded that liquid KMnO4 did not significantly increase poultry litter quality. Mechanisms relating to increasing litter pH and ammonia using liquid KMnO4 are an oxidant agent (not acid-foaming agents).
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