• Title, Summary, Keyword: equilibrium process

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Protein Adsorption on Ion Exchange Resin: Estimation of Equilibrium Isotherm Parameters from Batch Kinetic Data

  • Chu K.H.;Hashim M.A.
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.1
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    • pp.61-66
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    • 2006
  • The simple Langmuir isotherm is frequently employed to describe the equilibrium behavior of protein adsorption on a wide variety of adsorbents. The two adjustable parameters of the Langmuir isotherm - the saturation capacity, or $q_m$, and the dissociation constant, $K_d$ - are usually estimated by fitting the isotherm equation to the equilibrium data acquired from batch equilibration experiments. In this study, we have evaluated the possibility of estimating $q_m$ and $K_d$ for the adsorption of bovine serum albumin to a cation exchanger using batch kinetic data. A rate model predicated on the kinetic form of the Langmuir isotherm, with three adjustable parameters ($q_m,\;K_d$, and a rate constant), was fitted to a single kinetic profile. The value of $q_m$ determined as the result of this approach was quantitatively consistent with the $q_m$ value derived from the traditional batch equilibrium data. However, the $K_d$ value could not be retrieved from the kinetic profile, as the model fit proved insensitive to this parameter. Sensitivity analysis provided significant insight into the identifiability of the three model parameters.

The Prediction of Vapor-Liquid Equilibrium Data for Ethanol/3-methyl-1-butanol System at Constant Temperature (정온하에서 Ethanol/3-methyl-1-butanol계의 기-액평형치 추산)

  • Lee, Joon-Man;Park, Young-Hae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.4
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    • pp.2055-2061
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    • 2013
  • Recently, an understanding of new sources of liquid hydrocarbons such as bio-ethanol is economically very important. Successful design of distillation columns in a separation process depend on the availability of accurate vapor-liquid equilibrium data. For the binary system of Ethanol/3-methyl-l-butanol mixture, isothermal Vapor-liquid equilibrium data were measured at temperature of 50, 55, 60, 65, 70, 75 and $80^{\circ}C$. An empirical relation to predict Vapor-liquid equilibrium data was obtained from the above measured data. The predicted values are compared with the measured ones to be in a good agreement within accuracy of ${\pm}0.0005$, ${\pm}0.0022$.

Investigation of the observed solar coronal plasma in EUV and X-rays in non-equilibrium ionization state

  • Lee, Jin-Yi;Raymond, John C.;Reeves, Katharine K.;Shen, Chengcai;Moon, Yong-Jae
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.1
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    • pp.53.1-53.1
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    • 2018
  • During a major solar eruption, the erupting plasma is possibly out of the equilibrium ionization state because of its rapid heating or cooling. The non-equilibrium ionization process is important in a rapidly evolving system where the thermodynamical time scale is shorter than the ionization or recombination time scales. We investigate the effects of non-equilibrium ionization on EUV and X-ray observations by the Atmospheric Imaging Assembly (AIA) on board Solar Dynamic Observatory and X-ray Telescope (XRT) on board Hinode. For the investigation, first, we find the emissivities for all the lines of ions of elements using CHIANTI 8.07, and then we find the temperature responses multiplying the emissivities by the effective area for each AIA and XRT passband. Second, we obtain the ion fractions using a time-dependent ionization model (Shen et al. 2015), which uses an eigenvalue method, for all the lines of ion, as a function of temperature, and a characteristic time scale, $n_et$, where $n_e$ and t are density and time, respectively. Lastly, the ion fractions are multiplied to the temperature response for each passband, which results in a 2D grid for each combination of temperature and the characteristic time scale. This is the set of passband responses for plasma that is rapidly ionized in a current sheet or a shock. We investigate an observed event which has a relatively large uncertainty in an analysis using a differential emission measure method assuming equilibrium ionization state. We verify whether the observed coronal plasmas are in non-equilibrium or equilibrium ionization state using the passband responses.

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Removal Characteristics of Copper Ion in Wastewater by Employing a Biomass from Liquor Production Process as an Adsorbent (주류 제조과정에서 발생하는 바이오매스를 흡착제로 한 구리 제거 특성)

  • Baek, Mi-Hwa;Kim, Dong-Su
    • Journal of Korean Society on Water Environment
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    • v.22 no.4
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    • pp.626-631
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    • 2006
  • The adsorption features of copper ion have been investigated by taking the barley residue which occurring from the beer production process as an adsorbent. Under the experimental conditions, adsorption equilibrium of copper ion was attained within 30 minutes after the adsorption started and the adsorption reaction was observed to be first order. As the temperature increased, the adsorbed amount of copper ion at equilibrium was also increased, which indicated that the adsorption reaction was endothermic. Based on the experimental results which obtained by varying the temperatures, several thermodynamic parameters for copper adsorption reaction were estimated. Regarding the electrokinetic behavior of barley residue, its electrokinetic potential was observed to be positive below pH 5 and turned into negative above this pH. In the pH range from 1.5 to 4, copper adsorption was found to be increased, which was well explained by the electrokinetic behavior of barley residue in the pH range. When nitrilotriacetic acid, which is a complexing agent, was coexisted with copper ion, equilibrium adsorption of copper ion was decreased and this was presumed to be due to the formation of metal complex. In addition, the adsorbed amount of copper ion was examined to be increased when $KNO_3$ was coexisted, however, it approached a saturated value above a certain concentration of $KNO_3$.

A Political Economic Analysis of Environmental Policy, Redistributive Policy, and Economic Growth (환경정책, 재분배정책, 경제성장에 관한 정치경제학적 분석)

  • KIM, Jaehoon
    • KDI Journal of Economic Policy
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    • v.33 no.2
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    • pp.145-175
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    • 2011
  • We analyse an overlapping generation model in which economic agents, especially their income distribution, influence environmental policy and redistributive policy through political decision making process. In an economic equilibrium which doesn't consider political process, the introduction of environmental policy is shown to increase economic growth rate. In contrast to an economic equilibrium, environmental policy can be adopted when economic inequality reduces to a certain threshold in a political economic equilibrium. The adoption of environmental policy, on the other hand, incurs the demand of strengthened redistributive policy, which in turn decreases economic growth in a short run. We discuss broad policy implications based on our political economic analyses.

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Equilibrium, kinetic and thermodynamic studies of the adsorption of acidic dye onto bagasse fly ash

  • Shouman, Mona A.;Fathy, Nady A.;El-Khouly, Sahar M.;Attia, Amina A.
    • Carbon letters
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    • v.12 no.3
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    • pp.143-151
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    • 2011
  • Bagasse fly ash (BFA) is one of the important wastes generated in the sugar industry; it has been studied as a prospective low-cost adsorbent in the removal of congo red (CR) from aqueous solutions. Chemical treatment with $H_2O_2$ was applied in order to modify the adsorbability of the raw BFA. Batch studies were performed to evaluate the influence of various experimental parameters such as dye solution pH, contact time, adsorbent dose, and temperature. Both the adsorbents were characterized by Fourier-transform infrared spectrometer, energy-dispersive X-ray spectrophotometer and nitrogen adsorption at 77 K. Equilibrium isotherms for the adsorption of CR were analyzed by Langmuir, Freundlich and Temkin models using non-linear regression technique. Intraparticle diffusion seems to control the CR removal process. The obtained experimental data can be well described by Langmuir and also followed second order kinetic models. The calculated thermodynamic parameters indicate the feasibility of the adsorption process for the studied adsorbents. The results indicate that BFA can be efficiently used for the treatment of waste water containing dyes.

Adsorption Kinetics of Cupper and Zinc Ion with Na-A Zeolite Synthesized by Coal Fly Ash (석탄 비산재로 합성한 Na-A형 제올라이트에 의한 구리와 아연 이온의 동역학적 흡착 특성)

  • Lee, Chang-Han
    • Journal of Environmental Science International
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    • v.20 no.12
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    • pp.1607-1615
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    • 2011
  • The adsorption performance of cupper and zinc ions($Cu^{2+}$ and $Zn^{2+}$) in aqueous solution was investigated by an adsorption process on reagent grade Na-A zeolite(Z-WK) and Na-A zeolite (Z-C1) prepared from coal fly ash. Z-C1 was synthesized by a fusion method with coal fly ash from a thermal power plant. Batch adsorption experiment with Z-C1 was employed to study the kinetics and equilibrium parameters such as initial metal ions concentration and adsorption time of the solution on the adsorption process. Adsorption rate of metal ions occurred rapidly and adsorption equilibrium reached at less than 120 minutes. The kinetics data of $Cu^{2+}$ and $Zn^{2+}$ ions were well fitted by a pseudo-second-order kinetics model more than a pseudo-first-order kinetics model. The equilibrium data were well fitted by a Langmuir model and this result showed $Cu^{2+}$ and $Zn^{2+}$ adsorption on Z-C1 would be occupied by a monolayer adsorption. The maximum adsorption capacity($q_{max}$) by the Langmuir model was determined as $Cu^{2+}$ 99.8 mg/g and $Zn^{2+}$ 108.3 mg/g, respectively. It appeared that the synthetic zeolite, Z-C1, has potential application as absorbents in metal ion recovery and mining wastewater.

Multi-Attribute Data Fusion for Energy Equilibrium Routing in Wireless Sensor Networks

  • Lin, Kai;Wang, Lei;Li, Keqiu;Shu, Lei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.4 no.1
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    • pp.5-24
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    • 2010
  • Data fusion is an attractive technology because it allows various trade-offs related to performance metrics, e.g., energy, latency, accuracy, fault-tolerance and security in wireless sensor networks (WSNs). Under a complicated environment, each sensor node must be equipped with more than one type of sensor module to monitor multi-targets, so that the complexity for the fusion process is increased due to the existence of various physical attributes. In this paper, we first investigate the process and performance of multi-attribute fusion in data gathering of WSNs, and then propose a self-adaptive threshold method to balance the different change rates of each attributive data. Furthermore, we present a method to measure the energy-conservation efficiency of multi-attribute fusion. Based on our proposed methods, we design a novel energy equilibrium routing method for WSNs, viz., multi-attribute fusion tree (MAFT). Simulation results demonstrate that MAFT achieves very good performance in terms of the network lifetime.