http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Fe<sub>3</sub>O<sub>4</sub> 생성에 미치는 황산제일철/황산제이철 몰비와 침전제의 영향
엄태형(Tae Hyoung Eom),김삼중(Sam Joong Kim),안석진(Suk Jin An),오경환(Kyoung Hwan Oh),서동수(Dong Soo Suhr) 한국자기학회 2011 韓國磁氣學會誌 Vol.21 No.5
The effect of ferrous/ferric molar ratio and precipitants on the formation of nano size magnetite particle was investigated by co-precipitation method. Ferrous sulfate and ferric sulfate were used as iron sources and sodium hydroxide and ammonium hydroxide was used as a precipitant. Single phase magnetite was synthesized with all of experiment conditions (ferrous/ferric molar ratios and precipitants). Particle size was smaller, and particle size distribution was narrower when NaOH was used than NH<sub>4</sub>OH was used. The crystallinity and particle size was increased and narrower particle size distribution with increasing molar ratio ferrous/ferric sulfate with the same precipitant. Super paramagnetism could be obtained at all of experiment conditions. The highest saturation magnetization (72 emu/g) was obtained when the ferrous/ferric molar ratio was 2.5 and precipitant was used NH<sub>4</sub>OH.
Fe<sub>3</sub>O<sub>4</sub> 생성에 미치는 황산제일철/황산제이철 몰비의 영향
엄태형,김삼중,안석진,오경환,서동수,Eom, Tae-Hyoung,Tuan, Huynh Thanh,Kim, Sam-Joong,An, Suk-Jin,Oh, Kyoung-Hwan,Suhr, Dong-Soo 한국재료학회 2011 한국재료학회지 Vol.21 No.4
The effect of ferrous/ferric molar ratio on the formation of nano-sized magnetite particles was investigated by a co-precipitation method. Ferrous sulfate and ferric sulfate were used as iron sources and sodium hydroxide was used as a precipitant. In this experiment, the variables were the ferrous/ferric molar ratio (1.0, 1.25, 2.5 and 5.0) and the equivalent ratio (0.10, 0.25, 0.50, 0.75, 1.0, 2.0 and 3.0), while the reaction temperature ($25^{\circ}C$) and reaction time (30 min.) were fixed. Argon gas was flowed during the reactions to prevent the $Fe^{2+}$ from oxidizing in the air. Single-phase magnetite was synthesized when the equivalent ratio was above 2.0 with the ferrous/ferric molar ratios. However, goethite and magnetite were synthesized when the equivalent ratio was 1.0. The crystallinity of magnetite increased as the equivalent ratio increased up to 3.0. The crystallite size (5.6 to 11.6 nm), median particle size (15.4 to 19.5 nm), and saturation magnetization (43 to 71 $emu.g^{-1}$) changed depending on the ferrous/ferric molar ratio. The highest saturation magnetization (71 $emu.g^{-1}$) was obtained when the equivalent ratio was 3.0 and the ferrous/ferric molar ratio was 2.5.
P<sub>2</sub>O<sub>5</sub>가 클링커 광물조성 및 품질에 미치는 영향
엄태형,김원석,김창범,전병용,이종열,Eom, Tae-Hyoung,Kim, Won-Seok,Kim, Chang-Bum,Jeon, Byeong-Yong,Lee, Jong-Ryul 한국세라믹학회 2007 한국세라믹학회지 Vol.44 No.9
The influence of $P_2O_5$ on clinker mineral composition and the cement quality was investigated. When the sewage sludge was used as a raw material in place of clay, the presence of $P_2O_5$ in sewage sludge affects the mineral composition and the clinker quality. As the $P_2O_5$ concentration in raw mix increases, the burnability of clinker becomes worse and the alite decomposes into belite and free-CaO, so belite increases with the decrease of alite. The early strength of mortar decreases with the increase of $P_2O_5$ concentration. On the other hand, later-age strength increases with the increase of belite content. The setting time of cement was delayed with the $P_2O_5$ concentration above 0.6 wt%.
연소전 CO<sub>2</sub> 회수를 위한 고체 흡수제 및 WGS 촉매 특성 평가
엄태형(Eom, Tae Hyoung),이중범(Lee, Joong Beom),박근우(Park, Keun Woo),최동혁(Choi, Dong Hyuk),백점인(Baek, Jeom-In),류청걸(Ryu, Chong Kul) 한국신재생에너지학회 2010 한국신재생에너지학회 학술대회논문집 Vol.2010 No.06
석탄가스화복합발전(IGCC: Integrated Gasification Combined Cycle)의 고온 고압 합성가스로부터 CO₂를 저비용으로 포집하기 위한 연소전 포집 기술 중 유동층 촉진수성가스전환(SEWGS) 공정이 제안되어 연구개발 중에 있다. 연소전 CO₂ 포집을 위한 SEWGS 공정은 동일한 2탑 순환 유동층 반응기에서 고온 고압의 합성가스(H₂, CO)를 유동층 WGS 촉매를 사용하여 CO를 CO₂로 전환하는 동시에 전환반응으로 생성된 CO₂를 흡수제를 이용하여 포집하는 기술이다. 본 연구는 CO₂ 회수와 WGS 반응이 동시에 이루어지는 공정에 적용 가능한 건식 재생 흡수제 및 유동층 WGS 촉매 개발을 목표로 CO₂ 흡수제(P Series) 및 WGS 촉매(PC Series) 조성을 제안하고 분무건조기를 이용하여 6~8kg/batch로 성형 제조하였다. 제조된 CO₂ 흡수제 및 촉매의 특성 평가 결과 내마모도(Attrition resistance)를 포함한 물리적 특성이 유동층 공정의 요구조건을 만족하는 결과를 얻을 수 있었다. 또한, 모사 석탄 합성가스를 이용하여 20bar, 200?C 흡수/400?C 재생 조건에서 열중량 분석기(TGA) 및 가압 유동층(Fluidized-bed) 반응기를 통한 흡수제의 CO₂ 흡수능 평가를 수행하였다. 그 결과 내마모도(AI) 3% 이하로 기계적 강도가 우수하며, CO₂ 흡수능 17.6 wt%(TGA) 및 11wt%(가압 유동층)를 나타냈다. 유동층 WGS 특성 평가 결과 내마모도가 7~35%로 우수하였고, CO 전환율은 200?C에서 80% 이상으로, 유동층 SEWGS 공정에 적용 가능한 특성을 확인하였다.
엄태형,김삼중,서동수,Eom, Tae-Hyoung,Tuan, Huynh Thanh,Kim, Sam-Joong,Suh, Dong-Soo 한국재료학회 2010 한국재료학회지 Vol.20 No.6
The chemical formula of magnetite ($Fe_3O_4$) is $FeO{\cdot}Fe_2O_3$, t magnetite being composed of divalent ferrous ion and trivalent ferric ion. In this study, the influence of the coexistence of ferrous and ferric ion on the formation of iron oxide was investigated. The effect of the co-precipitation parameters (equivalent ratio and reaction temperature) on the formation of iron oxide was investigated using ferric sulfate, ferrous sulfate and ammonia. The equivalent ratio was varied from 0.1 to 3.0 and the reaction temperature was varied from 25 to 75. The concentration of the three starting solutions was 0.01mole. Jarosite was formed when equivalent ratios were 0.1-0.25 and jarosite, goethite, magnetite were formed when equivalent ratios were 0.25-0.6. Single-phase magnetite was formed when the equivalent ratio was above 0.65. The crystallite size and median particle size of the magnetite decreased when the equivalent ratio was increased from 0.65 to 3.0. However, the crystallite size and median particle size of the magnetite increased when the reaction temperature was increased from $25^{\circ}C$ to $75^{\circ}C$. When ferric and ferrous sulfates were used together, the synthetic conditions to get single phase magnetite became simpler than when ferrous sulfate was used alone because of the co-existence of $Fe^{2+}$ and $Fe^{3+}$ in the solution.
김삼중,엄태형,왕웨이,서동수,Kim, Sam-Joong,Eom, Tae-Hyoung,Wang, Wei,Suhr, Dong-Soo 한국재료학회 2008 한국재료학회지 Vol.18 No.4
A $Fe(OH)_2$ suspension was prepared by mixing iron sulfate and a weak alkali ammonia solution. Following this, iron oxides were synthesized by passing pure oxygen through the suspension (oxidation). The effects of different reaction temperatures ($30^{\circ}C$, $50^{\circ}C$, $70^{\circ}C$) and equivalent ratios ($0.1{\sim}10.0$) on the formation of iron oxides were investigated. An equilibrium phase diagram was established by quantitative phase analysis of the iron oxides using the Rietveld method. The equilibrium phase diagram showed a large difference from the equilibrium phase diagram of Kiyama when the equivalent ratio was above 1, and single $Fe_3O_4$ phase only formed above an equivalent ratio 2 at all reaction temperatures. Kiyama synthesized iron oxide using iron sulfate and a strong alkali NaOH solution.
김삼중,서동수,엄태형,송경섭,노재승,Kim Sam-Joong,Suhr Dong-Soo,Eom Tae-Hyoung,Song Kyung-Sub,Roh Jea-Seung 한국재료학회 2004 한국재료학회지 Vol.14 No.5
The influences of the ozone oxidation, reaction temperature and NaOH equivalent ratio on the iron oxide formation were studied with fixed ferrous sulfate concentration(0.5M $FeSO_4$ㆍ$7H_2$O). Geothite($\alpha$-FeOOH) and/or Magnetite ($Fe_3$$O_4$) were synthesized depending on the reaction conditions. The characteristics of the synthesized powders were evaluated by XRD, SEM and quantitative phase analysis. The synthetic conditions to get Goethite were quite different from the results of Kiyama's and the Goethite was conveniently synthesized at low temperature and at low NaOH equivalent ratio.
황산제일철 용애그이 오존산화에 의한 FeOOH 합성(오존농도 및 반응시간의 영향)
김삼중,송경섭,엄태형,서동수,Kim Sam-Joong,Song Kyung-Sub,Eom Tae-Hyoung,Suhr Dong-Soo 한국재료학회 2005 한국재료학회지 Vol.15 No.12
The influences of the oxidant($O_2\;and\;O_3$) on the FeOOH formation were studied with fixed $FeSO_4{\cdot}7H_2O$ concentration (0.5M) and NaOH equivalent ratio(0.5). The characteristics of the synthesized powders were evaluateed by XRD, and equantitative phase analysis. $\alpha-FeOOH$ (Geothite) and/or $\gamma-FeOOH$ was promoted when $O_3$ was used as a oxidant which is stronger oxidizing agent than $O_2$.