• 제목/요약/키워드: Phase equilibrium

검색결과 598건 처리시간 0.027초

Phase Distribution, Microstructure, and Electrical Characteristics of NASICON Compounds

  • N.H. Cho;Kang, Hee-Bok;Kim, Y.H.
    • The Korean Journal of Ceramics
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    • 제1권4호
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    • pp.179-184
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    • 1995
  • Sodium superionic conductor (NASICON) compounds were prepared. The effects of sintering temperature and cooling rate on the formation and the distribution of crystalline NASICON and $ZrO_3$ second phase were investigated. In the von Alpen-type composition, the $ZrO_2$ second phase is in thermal equilibrium with the crystalline NASICON above $1320^{\circ}C$, but when cooled through 1260-$1320^{\circ}C$ crystalline NASICON was formed by reaction between $ZrO_2$ and liquid phase. Very slow cooling ($1^{\circ}C$/hr) to $1260^{\circ}C$ from sintering temperature decreased the amount of sodium which prevents the formation of the crystalline NASICON resulted high number of $ZrO_2$ grains near the surface of some sintered bodies. Maximum electrical conductivity of 0.200 ohm-1cm-1 was obtained at $300^{\circ}C$ for well-sintered samples with little $ZrO_3$. On the other hand, low conductivities were obtained for rapid-cooled samples which have less dense microstructure.

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DME 액적의 증발특성 해석 (Numerical Study on the Droplet Vaporization Characteristics of Dimethyl Ether(DME) Droplet)

  • 유용욱;류종혁;김용모
    • 한국자동차공학회논문집
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    • 제12권2호
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    • pp.69-75
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    • 2004
  • The present study is numerically investigated for the high pressure effects on the vaporization process of the DME droplet. The evaporation rate of DME droplets is about twice that of dodecane droplets at the same chamber condition. The DM droplet vaporization characteristics is parametrically studied for the wide range of the operating conditions encountered with the high pressure combustion process.

전력용 나노 복합재료의 특성

  • 이상헌;최용
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 추계학술대회 논문집
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    • pp.212-212
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    • 2009
  • Nano composite sample were irradiated and annealed to study irradiation induced phase transformation behavior by nano indention technique. The specimens with 3mm in diameter were irradiatied. Polycrystalline nano filaments were broken their shape and tended to be equilibrium shape like facted sphere. The hardness of irradiatied nanocomposites was decreased by annealing which resulted from the grooving of silver filaments.

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GENERATION OF MAGNETIC FIELDS BY TEMPERATURE GRADIENTS

  • OKABE NOBUHIRO;HATTORI MAKOTO
    • 천문학회지
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    • 제37권5호
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    • pp.547-551
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    • 2004
  • We showed that magnetic fields are generated in the plasma which have the temperature inhomogeneities. The mechanism is the same as the Weibel instability because the velocity distribution functions are at non-equilibrium and anisotropic under the temperature gradients. The growth timescale is much shorter than the dynamical time of structure formation. The coherence length of magnetic fields at the saturated time is much shorter than kpc scale and then, at nonlinear phase, become longer by inverse-cascade process. We report the application of our results to clusters of galaxies, not including hydrodynamic effects.

Metallothionein gene(pPMT)와 Manganese Transport Gene mntA(pZH3-5)를 포함한 재조합 Escherichia coli를 이용하여 수용액상에서의 Cadmium의 선택적 제거

  • 김세권;백승학;김은기
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2000년도 춘계학술발표대회
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    • pp.426-429
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    • 2000
  • Recombinant E. coli JM109(pZH3-5/pMT) harboring manganese transport gene(mntA) and metal sequestering protein, metallothionein(MT), was cultivated to accumulate cadmium in aqueous phase. Bioaccumulation followed Michaelis-Menten type kinetics. Equilibrium isotherm showed Langmuir type isotherm. The optimum pH for $Cd^{2+}$ uptake was 7-7.5.

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고압 유동장에서의 액적증발 특성 해석 (Fuel Droplet Vaporization Characterization in High-Pressure Flow Field)

  • 유용욱;김용모
    • 대한기계학회논문집B
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    • 제22권8호
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    • pp.1121-1131
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    • 1998
  • The present study is numerically investigated for the high-pressure effects on the vaporization process in the convection-dominating flow field. Numerical results agree well with the available experimental data. The fuel droplet vaporization characterization is parametrically studied for the wide range of the operating conditions encountered with the high-pressure combustion process of turbocharged diesel engines.

Biased hooking for primitive chain network simulations of block copolymers

  • Masubuchi Yuichi;Ianniruberto Giovanni;Marrucci Giuseppe;Greco Francesco
    • Korea-Australia Rheology Journal
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    • 제18권2호
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    • pp.99-102
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    • 2006
  • Primitive chain network model for block copolymers is used here to simulate molecular dynamics in the entangled state with acceptable computational cost. It was found that i) the hooking procedure rearranging the topology of the entangled network is critical for the equilibrium structure of the system, and ii) simulations accounting for the different chemistry, i.e., with a biased hooking probability based on interaction parameter ${\chi}$ for selection of the hooked partner, generates a reasonable phase diagram.

Beta-cyclodextrin과 의약품(醫藥品)과의 상호작용(相互作用) (Interaction of Beta-cyclodextrin with Some Pharmaceuticals)

  • 김신근
    • Journal of Pharmaceutical Investigation
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    • 제4권1_2호
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    • pp.13-18
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    • 1974
  • Data are present for the interaction of beta-cyclodextrin with 7 pharmaceuticals in aqueous solution. By means of the solubility method of analysis, definite interaction were found to occur with all the compounds tested. The amount of these pharmaceuticals in equilibrium with their respective solid phase increased progressively with beta-cyclodextrin. A concentration of 1.5 g of beta-cyclodextrin per 100 ml of water increased the solubility of most compounds tested (except one) by 15-120%. Hydrolysis in alkali solution of chrolothiazide was retarded in the presence of beta-cyclodextrin.

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아연-니켈합금전착층의 조직특성 (Microstructure of Zn-Ni Alloy Electrodeposir)

  • 예길촌;최성렬;신현준;안덕수
    • 한국표면공학회지
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    • 제21권1호
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    • pp.10-18
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    • 1988
  • The variation of Composition and the microstructure of Zn-Ni alloy electrodespposits were investigated to the electrolysis conditions chloride bath. The codeposition mechanism is of the equilibrium type in the electrolysis condition of the high temperature(6$0^{\circ}C$)and high flow rate (1.2-3.0m/sec). The(411, 330) perferred orienation was mainly developed in the Zn-Ni electrodeposir with ${\gamma}$-phase structure, while the(422.600) orientation was closely related to the commposition and the structure of the alloy electrodeposit.

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Synergistic Extraction of Palladium(Ⅱ) with Thenoyltrifloroacetone and Tri-n-octylphosphine Oxide

  • 이상호;정구순
    • Bulletin of the Korean Chemical Society
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    • 제16권6호
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    • pp.479-483
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    • 1995
  • The synergistic extraction of palladium(Ⅱ) was studied with 1,2-dichloroethane containing thenoyltrifluoroacetone (TTA; HA) and tri-n-octylphosphine oxide (TOPO; S). The main composition of synergistic adduct extracted into 1,2-dichloroethane phase was found to be PdA2S2. The equilibrium constants of the synergistic reaction were calculated. The application of this method to synthetic mixture for the separation of Pd from Pt was developed.