• Title/Summary/Keyword: model reaction

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OPTIMALITY CONDITIONS FOR OPTIMAL CONTROL GOVERNED BY BELOUSOV-ZHABOTINSKII REACTION MODEL

  • RYU, SANG-UK
    • Communications of the Korean Mathematical Society
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    • v.30 no.3
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    • pp.327-337
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    • 2015
  • This paper is concerned with the optimality conditions for optimal control problem of Belousov-Zhabotinskii reaction model. That is, we obtain the optimality conditions by showing the differentiability of the solution with respect to the control. We also show the uniqueness of the optimal control.

A Review of Kinetic Model for Production of Highgrade Steel : Part. 1. Simulation Model Based on Coupled Reaction (고급강 제조 반응 모델의 검토 : Part. 1. Coupled Reaction 기반 시뮬레이션 모델)

  • Kim, Jeong-In;Kim, Sun-Joong
    • Resources Recycling
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    • v.30 no.1
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    • pp.3-13
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    • 2021
  • In the secondary refining process for the production of high-grade steel, the proper composition is maintained by alloying elements, and non-metallic inclusions are controlled for high cleanliness. Complex reactions occur simultaneously between the molten steel, slag, inclusions, refractories, and alloying elements during the secondary refining process. Previous works have reported simulation models based on kinetics to predict the compositional changes in molten steel, slag, and inclusions in actual processes. Analytical reviews are required for the models to predict the process accurately. In this study, we reviewed and analyzed simulation models based on the coupled reaction model for the secondary refining process.

Design of Reaction Wheel Simulink Model (반작용 휠의 시뮬링크 모델 개발)

  • Kwon, Jae-Wook;Lee, Dong-Hun;Rew, Dong-Young
    • Aerospace Engineering and Technology
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    • v.13 no.2
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    • pp.47-53
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    • 2014
  • This paper cites that reaction wheel which is widely used on precisely controling a spacecraft is designed with Simulink as a software model. Electrical Characteristics and Mechanical ones of reaction wheels are applied to the simulation model and those equations are summarized for helping understanding. Moreover, results of numerical simulations with rigid body model show that the designed software model of reaction wheels is known to be well operated under its set parameter values.

Optimization of Maillard Reaction in Model System of Glucosamine and Cysteine Using Response Surface Methodology

  • Arachchi, Shanika Jeewantha Thewarapperuma;Kim, Ye-Joo;Kim, Dae-Wook;Oh, Sang-Chul;Lee, Yang-Bong
    • Preventive Nutrition and Food Science
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    • v.22 no.1
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    • pp.37-44
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    • 2017
  • Sulfur-containing amino acids play important roles in good flavor generation in Maillard reaction of non-enzymatic browning, so aqueous model systems of glucosamine and cysteine were studied to investigate the effects of reaction temperature, initial pH, reaction time, and concentration ratio of glucosamine and cysteine. Response surface methodology was applied to optimize the independent reaction parameters of cysteine and glucosamine in Maillard reaction. Box-Behnken factorial design was used with 30 runs of 16 factorial levels, 8 axial levels and 6 central levels. The degree of Maillard reaction was determined by reading absorption at 425 nm in a spectrophotometer and Hunter's L, a, and b values. ${\Delta}E$ was consequently set as the fifth response factor. In the statistical analyses, determination coefficients ($R^2$) for their absorbance, Hunter's L, a, b values, and ${\Delta}E$ were 0.94, 0.79, 0.73, 0.96, and 0.79, respectively, showing that the absorbance and Hunter's b value were good dependent variables for this model system. The optimum processing parameters were determined to yield glucosamine-cysteine Maillard reaction product with higher absorbance and higher colour change. The optimum estimated absorbance was achieved at the condition of initial pH 8.0, $111^{\circ}C$ reaction temperature, 2.47 h reaction time, and 1.30 concentration ratio. The optimum condition for colour change measured by Hunter's b value was 2.41 h reaction time, $114^{\circ}C$ reaction temperature, initial pH 8.3, and 1.26 concentration ratio. These results can provide the basic information for Maillard reaction of aqueous model system between glucosamine and cysteine.

Treatment of nitrobenzene-cotaminated Wastewater using Oxidation Reaction (산화제를 이용한 니트로벤젠 함유 폐수 처리)

  • 신진환;손종렬
    • Journal of environmental and Sanitary engineering
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    • v.17 no.1
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    • pp.69-74
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    • 2002
  • This study explored for treatment processes by investigating the treatment efficiency and reaction mechanism through oxidation reaction using UV and $O_3$ as oxidant in compensate the wastewater containing nitrobenzene that is non biodegradable organic. Also by modeling these reactions, we try to step explanation of optimum reaction rate and reaction mechanism as the development of the computer program predictable the reaction rate by modeling the reaction. By using this model, after kinetic constant for each reaction from an experimental data is made an optimization and for hardly contribute to reaction rate in reaction kinetic equation is made an ignorance and suppose the simplified reaction mechanism, examined the propriety of computer simulation model and simplified reaction mechanism by comparing and inspecting the reaction kinetic constant and masstransfer coefficient. An investigation results for destructional treatment of nitrobenzene in the wastewater as non-biddegradable organic using UV, $O_3{\;}O_2{\;}H_2O_2-UV$ as oxidant.

Effect of Lipoxygenase on the Oxidation of Rainbow Trout Lipid in Model system (모델시스템에 있어서 무지개 송어 지방질의 산화에 대한 Lipoxygenase의 영향)

  • 김혜경;엄수현;최홍식
    • Journal of Life Science
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    • v.5 no.2
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    • pp.70-75
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    • 1995
  • The effect of lipoxygenase (LOX) on the oxidation and co-oxidation of lipid fraction was studied in the model system of rainbow trout. For the reaction in model system 1 g of lipid fraction and 50mL of enzyme extract(LOX, 140 unit in 50mL phosphate buffer solution at pH 7, 4)), which were obtained from rainbow trout, were homoginized in the presence of Tween 20 and kept at 23$\circ$C for 3 days. The activity of LOX was decreased to 43% of initial level during the reaction in the model system. The initial composition of rainbow trout lipid was showed to be consisted of trigliceride(TG;82%) and free fatty acid(FFA;0.1%), while this converted to 59% of TG and 20% of FIFA, respectively after reaction in model system. Change of fatty acid composition was also observed and the content of linoleic acid, one of the major fatte acids, was decreased to 13% from 54% in the content of total fatty acids after reaction. The carotenoids in rainbow trout were composed of 0.4% $\alpha$-carotene, 1.6% $\beta$ -carotene, 80% canthaxanthin, 7% lutein and 11% zeaxanthin, thus the canthaxanthin was the major component. This canthaxanthin was the most degraded carotenoid by lipoxygenase catalyzed co-oxidation during the reaction. On the other hand the tocopherol isomers found in the rainbow trout were $\alpha$ and $\beta$ -tocopherol, and $\alpha$-tocopherol had a higher degradation rate by the lipoxygenase catalyzed co-oxidation than of $\beta$-tocopherol in the reaction of model system.

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Modeling of diffusion-reaction behavior of sulfate ion in concrete under sulfate environments

  • Zuo, Xiao-Bao;Sun, Wei;Li, Hua;Zhao, Yu-Kui
    • Computers and Concrete
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    • v.10 no.1
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    • pp.79-93
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    • 2012
  • This paper estimates theoretically the diffusion-reaction behaviour of sulfate ion in concrete caused by environmental sulfate attack. Based on Fick's second law and chemical reaction kinetics, a nonlinear and nonsteady diffusion-reaction equation of sulfate ion in concrete, in which the variable diffusion coefficient and the chemical reactions depleting sulfate ion concentration in concrete are considered, is proposed. The finite difference method is utilized to solve the diffusion-reaction equation of sulfate ion in concrete, and then it is used to simulate the diffusion-reaction process and the concentration distribution of sulfate ion in concrete. Afterwards, the experiments for measuring the sulfate ion concentration in concrete are carried out by using EDTA method to verify the proposal model, and results show that the proposed model is basically in agreement with the experimental results. Finally, Numerical example has been completed to investigate the diffusion-reaction behavior of sulfate ion in the concrete plate specimen immersed into sulfate solution.

Distribution of elastoplastic modulus of subgrade reaction for analysis of raft foundations

  • Rahgooy, Kamran;Bahmanpour, Amin;Derakhshandi, Mehdi;Bagherzadeh-Khalkhali, Ahad
    • Geomechanics and Engineering
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    • v.28 no.1
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    • pp.89-105
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    • 2022
  • The behavior of the soil subgrade is complex and irregular against loads. When modeling, the soil is often replaced by a more straightforward system called a subgrade model. The Winkler method of linear elastic springs is a popular method of soil modeling in which the spring constant shows the modulus of subgrade reaction. In this research, the factors affecting the distribution of the modulus of subgrade reaction of elastoplastic subgrades are examined. For this purpose, critical theories about the modulus of subgrade reaction were examined. A square raft foundation on a sandy soil subgrade with was analyzed at different internal friction angles and Young's modulus values using ABAQUS software. To accurately model the actual soil behavior, the elastic, perfectly plastic constitutive model was applied to investigate a foundation on discrete springs. In order to increase the accuracy of soil modeling, equations have been proposed for the distribution of the subgrade reaction modulus. The constitutive model of the springs is elastic, perfectly plastic. It was observed that the modulus of subgrade reaction under an elastic load decreased when moving from the corner to the center of the foundation. For the ultimate load, the modulus of subgrade reaction increased as it moved from the corner to the center of the foundation.

Reactor Sizing for Hydrogen Production from Ethane over Ni Catalyst (니켈 촉매 상에서 에탄으로부터 수소생산을 위한 반응기 사이징)

  • Seong, Minjun;Lee, Kyungeun;Cho, Jung-Ho;Lee, Young-Chul;Jeon, Jong-Ki
    • Clean Technology
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    • v.19 no.1
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    • pp.51-58
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    • 2013
  • In this study, kinetics data was obtained for steam reforming reaction of ethane over the nickel catalyst. The variables of steam reforming reaction were reaction temperature, partial pressure of ethane, and mole ratio of steam and ethane. Parameters for the power rate law kinetic model and the Langmuir-Hinshelwood model were obtained from the kinetic data. Also, sizing of steam reforming reactor was performed by using PRO/II simulator. For the steam reforming reaction of ethane, Langmuir-Hinshelwood model determining the reaction rate by the surface reaction was better suited than a simple power rate law kinetic model. On water-gas-shift reaction, power rate law kinetic model was well fitted to the kinetic data. Reactor size can be calculated for production of hydrogen through PRO/II simulation.