• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.661-668
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• 2015

The surface rheological properties of polymer monolayer show complicated non-linear viscoelastic flow phenomena when they are subjected to spreading flow. These spreading flow properties are controlled by the characteristics of flow units. The kinetics of the formation of an interfacial film obtained after spreading poly(diisobutylene maleic acid) at air-water interface were studied by measuring of the surface pressure with time. The experimental data were analyzed theoretically according to a nonlinear surface viscoelastic model. The values of dynamic modulus, static modulus, surface viscosities and rheological parameters in various area/ monomer were obtained by appling experimental data to the equation of nonlinear surface viscoelastic model.

• Nuclear Engineering and Technology
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• v.28 no.5
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• pp.452-457
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• 1996

A system, such as a reactor point kinetics equation, can be solved with Adomian Decomposition Method (ADM) which uses the notion that all solutions and operators can be expressed as an infinite sum of those basis states, like Adomian polynomials. In this work, ADM is applied to point reactor kinetics equations for step reactivity insertion, ramp input of reactivity, and nonlinear feedback cases without linearization approximation. The results of ADM are more accurate and faster than those of other existing methods, even though we use comparatively large time step sizes.

• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.377-381
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• 2002

Recently, interests to remove nitrogen in the nitritation process have increased because of its economical advantages, since it could be a short-cut process to save both oxygen for nitrification and carbon for denitrification compared to a typical nitrification. However, the kinetics related with the nitritation process has not yet been fully understood. Furthermore, many useful models which have been successfully used for wastewater treatment processes cannot be used to estimate effluent nitrite concentration for evaluating performance of the nitritation process, since the process rate equations and population of microorganisms for nitrogen removal in these models have been set up only for the condition of full nitrification. Therefore, the present study was conducted to estimate an effluent nitrite concentration in the nitritation process with a concept of enzymatic inhibition kinetics based on long-term laboratory experiments. Using a nonlinear least squares regression method, kinetic parameters were accurately determined. By setting up a process rate equation along with a mass balance equation of the nitrite-oxidizing step, an effluent nitrite concentration in the nitritation process was then successfully estimated.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.9
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• pp.1104-1109
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• 1992

A mathematical model of cancerous system based on immunological surveillance has been proposed by Lee. The model involves a system of 12 coupled nonlinear differential equations due to cellular kinetics and each of them can be modeled bilinearly. This paper discusses only the properties of solutions to the nonlinear differential equations and identification.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.50.3-50
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• 2001

Nonlinear feedback control scheme for reactive distillation column has been proposed. The proposed control scheme is derived in the framework of Nonlinear Internal Model Control. The product compositions and liquid and vapor flow rates in sections of the reactive distillation column are estimated from selected tray temperature measurements by an observer. The control scheme is applied to example reactive distillation column in which two products are produced in a single column and the reversible reaction A + B = C + D occurs. The relative volatilities are favorable for reactive distillation so that the reactants are intermediated boilers between the light product C and the heavy product D. Ideal physical properties, kinetics and ...

• Journal of the Korean Chemical Society
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• v.15 no.5
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• pp.219-222
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• 1971

The kinetics of the solvolysis of benzyl and p-or m-substituted benzyl bromides in various alcohols have been determined by an electric conductivity method. From these reactions, a curved Hammett plot is obtained and a mechanism is proposed to account for the nonlinear behavior observed. In addition, effects of solvent polarity on the activation parameters for the solvolysis of benzyl bromides are discussed.

• Journal of Mechanical Science and Technology
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• v.15 no.4
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• pp.510-521
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• 2001

A nonlinear acoustic instability of subcritical liquid-oxygen droplet flames burning in gaseous hydrogen environment are investigated numerically. Emphases are focused on the effects of finite-rate kinetics by employing a detailed hydrogen-oxygen chemistry and of the phase change of liquid oxygen. Results show that if nonlinear harmonic pressure oscillations are imposed, larger flame responses occur during the period that the pressure passes its temporal minimum, at which point flames are closer to extinction condition. Consequently, the flame response function, normalized during one cycle of pressure oscillation, increases nonlinearly with the amplitude of pressure perturbation. This nonlinear response behavior can be explained as a possible mechanism to produce the threshold phenomena for acoustic instability, often observed during rocket-engine tests.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.393-396
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• 1988

In discharge excited excimer laser, it is hard to say that the analysis of laser operation was well explained until now. But this can be improved by analysis the nonlinear discharge characteristics in the cavity. The nonlinear characteristics can be analysed by solving the nonlinear resistance which depends on electron mobility and number density. We can calculate the electron mobility and number density each other using Boltzmann equation and Kinetics equation. So we calculated the nonlinear resistance and analysed nonlinear discharge characteristics.

• Applied Chemistry for Engineering
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• v.34 no.2
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• pp.131-136
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• 2023

We developed a method to measure the concentration of highly concentrated colored samples using color coordinates. We present a color analysis to estimate the concentration of highly concentrated binary solutions with an empirical function and apply it to estimate the kinetics of a catalytic irreversible reaction of resazurin to resorufin. The developed method enabled one to measure the concentration of solutions whose range of concentrations is nonlinear and beyond the limit of UV-vis spectroscopic measurement directly without dilution.

• Toxicological Research
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• v.18 no.4
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• pp.311-324
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• 2002

Toxicokinetic studies are intended to provide critical evaluation of drug disposition at toxico-logical doses and help understand the relationship between blood or tissue levels and the time course of toxic events. Relatively high dose levels wed in toxicokinetics, compared to pharmacokinetics, complicates absorption, protein binding, metabolism and elimination processes. In this mini review, frequently wed toxicokinetic models such as linear compartment models, physiological models, and nonlinear kinetic mod-ec are introduced. In addition, optimization of toxicokinetic studies, their role in the drug development process, and prediction oj human toxicokinetics based on animal data by interspecies scaling are briefly discussed.