An inverse problem for estimating the time-dependent reaction coefficient in an autocatalytic reaction pathway

2005 ◽  
Vol 60 (2) ◽  
pp. 447-457 ◽  
Author(s):  
Cheng-Hung Huang ◽  
Sin Kim
Keyword(s):  
Inverse Problem ◽  
Reaction Pathway ◽  
Autocatalytic Reaction ◽  
Time Dependent ◽  
Reaction Coefficient

Analysis of Different Kinds of Measurements on the Estimation of Time Dependent Mass and Heat Transfer Coefficients in Drying

2004 ◽  
Author(s):  
Leonardo F. Saker ◽  
Helcio R. B. Orlande ◽  
Cheng-Hung Huang ◽  
Gligor H. Kanevce ◽  
Ljubica P. Kanevce
Keyword(s):  
Inverse Problem ◽  
Adjoint Problem ◽  
Time Dependent ◽  
Problem Solution ◽  
Function Estimation ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Dependent Mass ◽  
Estimation Of Time ◽  
Local Moisture

In this paper we present the solution of the inverse problem of simultaneously estimating the heat and mass transfer coefficients at the surface of a drying one-dimensional body. The physical problem is formulated in terms of the linear Luikov equations and the unknown functions are time dependent. The inverse problem is solved by using the conjugate gradient method of function estimation with adjoint problem. Results are presented for the estimation of discontinuous functions by using simulated measurements of local temperature, local moisture content and/or total moisture weight. The main objective of the paper is to examine the effects of different types of measurements on the inverse problem solution.

scholarly journals Time-dependent activation of the semicarbazide-sensitive amine oxidase (SSAO) from ox lung microsomes

2000 ◽  
Vol 351 (3) ◽  
pp. 789-794 ◽  
Author(s):  
Jose M. LIZCANO ◽  
Keith F. TIPTON ◽  
Mercedes UNZETA
Keyword(s):  
Amine Oxidase ◽  
Reaction Pathway ◽  
Substrate Inhibition ◽  
Kinetic Studies ◽  
Tryptophan Fluorescence ◽  
The Other ◽  
Time Dependent ◽  
High Substrate ◽  
Before And After ◽  
Lag Period

The activity of ox lung microsomal semicarbazide-sensitive amine oxidase (EC 1.4.3.6; SSAO) towards benzylamine increased 20-fold during incubation at 37°C. After an initial lag-period, activation was first-order with time and complete after approx. 20h. No significant changes in activity towards methylamine, histamine or 2-phenylethylamine were observed, although mixed-substrate experiments were consistent with the same enzyme being involved in the oxidation of all these substrates, both before and after time-dependent activation. The enzyme-tryptophan fluorescence increased on incubation at 37°C in parallel with the increase in activity towards benzylamine. Treatment of the activated-enzyme preparation with 6M guanidinium chloride followed by dialysis, caused both the activity towards benzylamine and the fluorescence to fall to that occurring before activation. However, incubation of this preparation at 37°C resulted in increases in fluorescence and activity similar to those seen with the unactivated enzyme. Benzylamine oxidation was inhibited, uncompetitively with respect to oxygen, by high substrate concentrations but no such inhibition was observed with the other amines. Activation resulted in an increase in Vmax for benzylamine oxidation, with no significant alterations in the Km or the Ksi for high-substrate inhibition. Kinetic studies were consistent with sequential mechanisms being followed for the oxidation of both benzylamine and methylamine but the dependence on oxygen concentration was complex. These results might indicate that benzylamine follows a different reaction pathway from the other substrates, with substrate-specific activation involving a reaction step that is rate-limiting for benzylamine oxidation but not for the others.

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