• Title/Summary/Keyword: Isotherms

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Structure Analysis for Surface of LB Films Complexed Metal Ion (금속이온 착체에 의한 LB막의 표면 구조 분석)

  • Shin, Hoon-Kyu;Yoo, Seung-Yeop;Kwon, Young-Soo
    • Proceedings of the KIEE Conference
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    • 1998.11c
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    • pp.881-883
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    • 1998
  • We fabricated IMI-O polymer containing imidazole group that can be form a complex structure between the monolayer and the metal ions at the air-water interface. Also, the monolayer behavior at the air-water interface and Langmuir-Blodget films by complexes formation have been investigated by $\pi$-A isotherms, Brewster Angle Microscopy and the scanning Maxwell-stress microscopy.

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The Effect of Alloy Microstructure on the Behavior of Pd and Pd-based Alloy towards H2

  • Lee, Hyun Kyu;Noh, Hak
    • Journal of Hydrogen and New Energy
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    • v.11 no.3
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    • pp.97-105
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    • 2000
  • The influence of different microstructures and compositional variations on hydrogen absorption by pure Pd, and $Pd_{0.9}Rh_{0.1}$ alloy has been examined from changes in the hydrogen isotherms. The dilute phase solubilities and the plateau pressures are affected by differences in microstructures and compositional variations but the hydrogen capacities at relatively high hydrogen pressures are not affected except for the alloy form which has some phase separation.

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Significant Structure Theory of Physical Adsorption

  • Yun-liang Wang;Taikyue Ree;Henry Eyring
    • Journal of the Korean Chemical Society
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    • v.15 no.5
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    • pp.265-274
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    • 1971
  • A significant structure theory of monolayer physical adsorption is developed. The theory is tested with the adsorptions on graphite of gases Ar, $N_2$, $CHCl_3$, and $CCl_4$. A restricted rotation model is used for the polyatomic molecules $N_2$, $CHCl_3$, and $CCl_4$. The computed isotherms and heats of adsorption are in good agreement with experiment in all cases studied.

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A study on elemental mercury adsorption behaviors of nanoporous carbons with carbon dioxide activation

  • Bae, Kyong-Min;Park, Soo-Jin
    • Carbon letters
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    • v.15 no.4
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    • pp.295-298
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    • 2014
  • In this work, nanoporous carbons (NPCs) were prepared by the self-assembly of polymeric carbon precursors and block copolymer template in the presence of tetraethyl orthosilicate and colloidal silica. The NPCs' pore structures and total pore volumes were analyzed by reference to $N_2$/77 K adsorption isotherms. The porosity and elemental mercury adsorption of NPCs were increased by activation with carbon dioxide. It could be resulted that elemental mercury adsorption ability of NPCs depended on their specific surface area and micropore fraction.

Batch Chromatography Simulation of Tröger base by Aspen Chromatography (Aspen Chromatography에 의한 Tröger base의 회분식 크로마토그라피 전산모사)

  • Kim, Jung-Ae;Park, Moon-Bae;Kim, In Ho
    • Korean Chemical Engineering Research
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    • v.47 no.5
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    • pp.615-619
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    • 2009
  • (+)-$Tr{\ddot{o}}ger$'s base in $Tr{\ddot{o}}ger$'s base racemates that inhibits thromboxane A2($T{\times}A2$) synthase has been used to treat arteriosclerosis. Separation of (+)-$Tr{\ddot{o}}ger$'s base by chromatography has become a major concern. However separation experiments of (+)-$Tr{\ddot{o}}ger$'s base need time and consumables so that simulation with Aspen Chromatography could save time and costs by predicting the efficiency of separation. Injection amount and eluent flow rate were varied to compare the resolutions and yields of TB(-) and TB(+). Highest resolution and yield were attained at the eluent rate of 0.25 mL/min. Isotherms representing the relationship between mobile phase concentration and stationary phase concentration were changed to get the best separation with Ideal Adsorbed Solution(IAS) Statistical Lanmuir isotherms.

Removal of Benzene in Solution by using the Bio-carrier with Dead Bacillus drentensis sp. and Polysulfone (Bacillus drentensis sp. 사균과 polysulfone으로 이루어진 미생물담체를 이용한 수용액 내 벤젠 제거)

  • Park, Sanghee;Lee, Minhee
    • Journal of Soil and Groundwater Environment
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    • v.18 no.1
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    • pp.46-56
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    • 2013
  • Laboratory scale experiments to remove benzene in solution by using the bio-carrier composed of dead biomass have been performed. The immobilized bio-carrier with dead Bacillus drentensis sp. and polysulfone was manufactured as the biosorbent. Batch sorption experiments were performed with bio-carriers having various quantities of biomass and then, their removal efficiencies and uptake capacities were calculated. From results of batch experiments, 98.0% of the initial benzene (1 mg/L) in 1 liter of solution was removed by using 40 g of immobilized bio-carrier containing 5% biomass within 1 hour and the biosorption reaction reached in equilibrium within 2 hours. Benzene removal efficiency slightly increased (99.0 to $99.4%{\pm}0.05$) as the temperature increased from 15 to $35^{\circ}C$, suggesting that the temperature rarely affects on the removal efficiency of the bio-carrier. The removal efficiency changed under the different initial benzene concentration in solution and benzene removal efficiency of the bio-carrier increased with the increase of the initial benzene concentration (0.001 to 10 mg/L). More than 99.0% of benzene was removed from solution when the initial benzene concentration ranged from 1 to 10 mg/L. From results of fitting process for batch experimental data to Langmuir and Freundlich isotherms, the removal isotherms of benzene were more well fitted to Freundlich model ($r^2$=0.9242) rather than Langmuir model ($r^2$=0.7453). From the column experiment, the benzene removal efficiency maintained over 99.0% until 420 pore volumes of benzene solution (initial benzene concentration: 1 mg/L) were injected in the column packed with bio-carriers, investigating that the immobilized carrier containing Bacillus drentensis sp. and polysulfone is the outstanding biosorbent to remove benzene in solution.

Adsorption Characteristics of Nickel and Zinc Ion on Domestic Activated Carbon (활성탄에 의한 니켈 및 아연 이온의 흡착특성)

  • Chan-Kuk Kim;Tae-Won Min
    • Journal of the Korean Chemical Society
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    • v.28 no.2
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    • pp.121-129
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    • 1984
  • The adsorption characteristics of heavy metal ions $(Ni^{2+}$, $Zn^{2+}$) on domestic activated carbon which manufactured from the wood, waste rubber and coal has been studied. The following conclusions were obtained by investigating the effect of pH, halides, cyanide and temperature on the absorption of heavy metal ions and by determining absorption rate and absorption isotherms. When heavy metal ions were adsorbed on activated carbon in the pH range from 6 to 7, treated heavy metal ions were almost come to the equilibrium and recovered in the form of complex anions such as $MX_4^{2- }$and $M(CN)_4^{2-}$ in an hour. The absorption isotherms of heavy matel ions were well fitted in Freundlich's equation. Heavy metal complex anions on activated carbon were easily eluted by using 0.1N HCl solution. These results suggest that the complex anions have unexpectedly strong affinity for the surface of activated carbon.

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Application of Response Surface Analysis for Predicting Moisture Content of Binary Mixture (다중 회귀분석에 의한 이상혼합물(二相混合物)의 수분함량 예측)

  • Yoon, Heeny H.N.;Kim, H.;Shin, Y.D.;Yoo, M.Y.
    • Korean Journal of Food Science and Technology
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    • v.18 no.2
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    • pp.82-87
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    • 1986
  • The water sorption isotherms of binary mixtures, prepared by corn starch and isolated soybean protein (ISP) or casein, were measured and analyzed. Simple equations to predict moisture content from knowledge of composition and water activity of the mixture were derived by applying Response Surface Analysis. Comparison between predicted and experimental moisture content for 13 combinations of corn starch-lSP mixture at the range of $a_w$ 0.25-0.87 resulted in a maximum error of only 6.06% and an absolute mean error of 2.60%, and for the mixture of corn starch-casein the error was -4.39% and 2.12%, respectively. The agreement between experimental and predicted water sorption isotherms was shown to be 'highly acceptable' for the binary mixtures of 50% corn starch-50% ISP and 50% corn starch -50% casein.

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Prediction of Sorption Characteristics by Mass Balance Concept (함량비례 개념에 의한 수분흡습 특성의 예측)

  • Yoon, Heeny H.N.;Kim, H.;Shin, Y.D.;Yoo, M.Y.
    • Korean Journal of Food Science and Technology
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    • v.18 no.2
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    • pp.77-81
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    • 1986
  • The water sorption isotherms of individual insoluble components of corn starch, isolated soybean protein (ISP) and casein and their binary mixtures of corn starch-lSP and corn starch-casein were measured and analyzed. BET monolayer values and Smith plot parameters from the results of sorption isotherms were calculated by mass balance concept . The comparisons between experimental and predicted values resulted in an error of 2.29% for equilibrium moisture content and an error of 2.95% in monolayer value for the mixture 50% corn starch-50% ISP. On the other hand , for the mixture 50% corn starch-50% casein the errors were 2.66% and-5.34%, respectively.

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Physical Adsorption of Kr Gas on Graphite Surface : 2D Equation of State (흑연 표면에서의 Kr 기체의 물리흡착)

  • Woon Sun Ahn;Yong Keun Son;Eun Ah Yoo;Kwang Soon Lee
    • Journal of the Korean Chemical Society
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    • v.25 no.4
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    • pp.246-252
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    • 1981
  • Assuming krypton molecules adsorbed on graphite surface as 2D gas, the interaction energy of Kr-graphite and the Henry's constant are calculated analytically by the Fourier series expansion method. 2D virial cofficients, $B_{2D}$ and $C_{2D}$, are also calculated to obtain 2D equation of state, and hence adsorption isotherms. The isotherms so obtained are compared with experimental results reported by Putnam and Fort. The pairwise additivity of Lennard-Jones(12, 6) interaction energy is also assumed, and parameters therein are taken as; ${\varepsilon}_{gs}$/k = 70 K, ${\sigma}_{gs}$ = 0.35 nm, ${\varepsilon}_{gg}$/k = 170 K, and ${\sigma}_{gg}$ = 0.37 nm.

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