scholarly journals Rapid multistep kinetic model generation from transient flow data

2017 ◽  
Vol 2 (2) ◽  
pp. 103-108 ◽  
Author(s):  
Christopher A. Hone ◽  
Nicholas Holmes ◽  
Geoffrey R. Akien ◽  
Richard A. Bourne ◽  
Frans L. Muller
Keyword(s):  
Kinetic Model ◽  
Kinetic Parameters ◽  
Transient Flow ◽  
Accurate Estimation ◽  
Model Generation ◽  
Flow Data

SNAr reaction profiles were generated using an automated reactor, collected in less than 3 hours, and allowed accurate estimation of kinetic parameters.

scholarly journals Estimation of the Kinetic Parameters of a Catalytic Cracking Model Case Study

2019 ◽  
Vol 70 (10) ◽  
pp. 3532-3537
Author(s):  
Cristina Popa ◽  
Nicoleta Nicolae ◽  
Cristian Patrascioiu
Keyword(s):  
Kinetic Model ◽  
Kinetic Parameters ◽  
Catalytic Cracking ◽  
Accurate Estimation ◽  
Model Parameters ◽  
Outlet Temperature ◽  
Objective Functions ◽  
Model Case ◽  
Cracking Process ◽  
Matlab Programming

This paper presents the research regarding determination of kinetic model parameters from a catalytic cracking process. Starting from the Weekman kinetic model, the authors proposed a simplified version of this model and, based on experimental data form a catalytic cracking plant, they have numerical determined the coefficients of the new kinetic model. For this purpose, there were defined two objective functions; the first function is based on errors generated by estimation of the riser outlet temperature and the second function associated to the errors generated by the estimation of the gasoline yield. The minimization of the two objective functions has been solve by using Optimization Toolbox from MATLAB programming language. The results showed that the objective function that depends on gasoline yield allows more accurate estimation of the kinetic parameters from this model.

scholarly journals Estimation of the Kinetic Parameters of a Catalytic Cracking Model Case Study

2019 ◽  
Vol 70 (10) ◽  
pp. 3532-3537
Keyword(s):  
Kinetic Model ◽  
Kinetic Parameters ◽  
Catalytic Cracking ◽  
Accurate Estimation ◽  
Model Parameters ◽  
Outlet Temperature ◽  
Objective Functions ◽  
Model Case ◽  
Cracking Process ◽  
Matlab Programming

This paper presents the research regarding determination of kinetic model parameters from a catalytic cracking process. Starting from the Weekman kinetic model, the authors proposed a simplified version of this model and, based on experimental data form a catalytic cracking plant, they have numerical determined the coefficients of the new kinetic model. For this purpose, there were defined two objective functions; the first function is based on errors generated by estimation of the riser outlet temperature and the second function associated to the errors generated by the estimation of the gasoline yield. The minimization of the two objective functions has been solve by using Optimization Toolbox from MATLAB programming language. The results showed that the objective function that depends on gasoline yield allows more accurate estimation of the kinetic parameters from this model. Keywords: kinetic model, optimization, catalytic cracking

scholarly journals Plasma radio-metabolite analysis of PET tracers for dynamic PET imaging: TLC and autoradiography

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Fiona Li ◽  
Justin W. Hicks ◽  
Lihai Yu ◽  
Lise Desjardin ◽  
Laura Morrison ◽  
...  
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Blood Plasma ◽  
Kinetic Parameters ◽  
High Performance ◽  
The Body ◽  
Accurate Estimation ◽  
Dynamic Pet ◽  
Arterial Concentration ◽  
In Blood Plasma

Abstract Background In molecular imaging with dynamic PET, the binding and dissociation of a targeted tracer is characterized by kinetics modeling which requires the arterial concentration of the tracer to be measured accurately. Once in the body the radiolabeled parent tracer may be subjected to hydrolysis, demethylation/dealkylation and other biochemical processes, resulting in the production and accumulation of different metabolites in blood which can be labeled with the same PET radionuclide as the parent. Since these radio-metabolites cannot be distinguished by PET scanning from the parent tracer, their contribution to the arterial concentration curve has to be removed for the accurate estimation of kinetic parameters from kinetic analysis of dynamic PET. High-performance liquid chromatography has been used to separate and measure radio-metabolites in blood plasma; however, the method is labor intensive and remains a challenge to implement for each individual patient. The purpose of this study is to develop an alternate technique based on thin layer chromatography (TLC) and a sensitive commercial autoradiography system (Beaver, Ai4R, Nantes, France) to measure radio-metabolites in blood plasma of two targeted tracers—[18F]FAZA and [18F]FEPPA, for imaging hypoxia and inflammation, respectively. Results Radioactivity as low as 17 Bq in 2 µL of pig’s plasma can be detected on the TLC plate using autoradiography. Peaks corresponding to the parent tracer and radio-metabolites could be distinguished in the line profile through each sample (n = 8) in the autoradiographic image. Significant intersubject and intra-subject variability in radio-metabolites production could be observed with both tracers. For [18F]FEPPA, 50% of plasma activity was from radio-metabolites as early as 5-min post injection, while for [18F]FAZA, significant metabolites did not appear until 50-min post. Simulation study investigating the effect of radio-metabolite in the estimation of kinetic parameters indicated that 32–400% parameter error can result without radio-metabolites correction. Conclusion TLC coupled with autoradiography is a good alternative to high-performance liquid chromatography for radio-metabolite correction. The advantages of requiring only small blood samples (~ 100 μL) and of analyzing multiple samples simultaneously, make the method suitable for individual dynamic PET studies.

Kinetic parameters estimation in an anaerobic digestion process using successive quadratic programming

2005 ◽  
Vol 52 (1-2) ◽  
pp. 419-426 ◽  
Author(s):  
C.A. Aceves-Lara ◽  
E. Aguilar-Garnica ◽  
V. Alcaraz-González ◽  
O. González-Reynoso ◽  
J.P. Steyer ◽  
...  
Keyword(s):  
Experimental Data ◽  
Anaerobic Digestion ◽  
Quadratic Programming ◽  
Kinetic Parameters ◽  
Parameters Estimation ◽  
Fixed Bed Reactor ◽  
Accurate Estimation ◽  
Successive Quadratic Programming ◽  
Anaerobic Digestion Process ◽  
Digestion Process

In this work, an optimization method is implemented in an anaerobic digestion model to estimate its kinetic parameters and yield coefficients. This method combines the use of advanced state estimation schemes and powerful nonlinear programming techniques to yield fast and accurate estimates of the aforementioned parameters. In this method, we first implement an asymptotic observer to provide estimates of the non-measured variables (such as biomass concentration) and good guesses for the initial conditions of the parameter estimation algorithm. These results are then used by the successive quadratic programming (SQP) technique to calculate the kinetic parameters and yield coefficients of the anaerobic digestion process. The model, provided with the estimated parameters, is tested with experimental data from a pilot-scale fixed bed reactor treating raw industrial wine distillery wastewater. It is shown that SQP reaches a fast and accurate estimation of the kinetic parameters despite highly noise corrupted experimental data and time varying inputs variables. A statistical analysis is also performed to validate the combined estimation method. Finally, a comparison between the proposed method and the traditional Marquardt technique shows that both yield similar results; however, the calculation time of the traditional technique is considerable higher than that of the proposed method.

Kinetic modelling of the photocatalytic inactivation of bacteria

2010 ◽  
Vol 61 (6) ◽  
pp. 1547-1553 ◽  
Author(s):  
Javier Marugán ◽  
Rafael van Grieken ◽  
Alberto E. Cassano ◽  
Orlando M. Alfano
Keyword(s):  
Kinetic Model ◽  
Kinetic Parameters ◽  
Catalyst Concentration ◽  
Kinetic Modelling ◽  
Kinetic Constant ◽  
Water Disinfection ◽  
Radiation Absorption ◽  
Simple Modification ◽  
Model Based ◽  
Photocatalytic Inactivation

This work analyzes the kinetic modelling of the photocatalytic inactivation of E. coli in water using different types of kinetic models; from an empirical equation to an intrinsic kinetic model including explicit radiation absorption effects. Simple empirical equations lead to lower fitting errors, but require a total of 12 parameters to reproduce the results of four inactivation curves when the catalyst concentration was increased. Moreover, these parameters have no physical meaning and cannot be extrapolated to different experimental conditions. The use of a pseudo-mechanistic model based on a simplified reaction mechanism reduces the number of required kinetic parameters to 6, being the kinetic constant the only parameter that depends on the catalyst concentration. Finally, a simple modification of a kinetic model based on the intrinsic mechanism of photocatalytic reactions including explicit radiation absorption effects achieved the fitting of all the experiments with only three parameters. The main advantage of this approach is that the kinetic parameters estimated for the model become independent of the irradiation form, as well as the reactor size and its geometrical configuration, providing the necessary information for scaling-up and design of commercial-scale photoreactors for water disinfection.

Réaction oscillante de Belousov. 2. Etude d'un nouveau modèle cinétique

1977 ◽  
Vol 55 (17) ◽  
pp. 3147-3155 ◽  
Author(s):  
Guy Schmitz
Keyword(s):  
Kinetic Model ◽  
Kinetic Parameters ◽  
Analog Computer ◽  
Limiting Cycle ◽  
Oscillating Reaction

On the basis of our results dealing with the bromate-cerous reaction we propose and discuss a new kinetic model for the Belousov–Zhabotinskii oscillating reaction. The existence of a limiting cycle is shown with an analog computer for a set of semi-empirically chosen kinetic parameters.

scholarly journals Implementation of Stereochemistry in Automatic Kinetic Model Generation

2016 ◽  
Vol 48 (12) ◽  
pp. 755-769 ◽  
Author(s):  
Nick M. Vandewiele ◽  
Ruben Van De Vijver ◽  
Hans-Heinrich Carstensen ◽  
Kevin M. Van Geem ◽  
Marie-Françoise Reyniers ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Model Generation

Kinetics and Modelling of Bulk and Solution Diallyl Terephthalate Polymerization

2006 ◽  
Vol 4 (1) ◽  
Author(s):  
Iztok Hace
Keyword(s):  
Kinetic Model ◽  
Kinetic Parameters ◽  
Rate Constants ◽  
Chain Transfer ◽  
Average Molecular Weight ◽  
Propagation Rate ◽  
Reaction Conditions ◽  
Diffusion Limitations ◽  
Kinetics Of ◽  
Dicyclohexyl Peroxydicarbonate

Free radical polymerization kinetics of diallyl terephthalate (DAT) in solution was investigated with two different peroxide initiators: dicyclohexyl peroxydicarbonate (CHPC) and benzoyl peroxide (BPO) in temperature range from 50°C to 110°C, where ortho-xylene was used as a solvent. Conversion points were measured using Fourier Transform Infrared (FTIR) measurements. Previously developed kinetic model for bulk DAT polymerization, was extended to solution DAT polymerization. The ratio of solvent chain - transfer rate constants to propagation rate constants of the polymerization system were found between 1.25 10-4 to 1.68 10-4 for various reaction conditions. They were obtained using the calculated initial polymerization rates and the number average molecular weight measurements made by GPC. The effect of different solvent fractions and initiator concentrations on the diffusion limitations were investigated. Only two kinetic parameters, kpd0 and ktd0 were obtained by fitting the kinetic model onto measured conversions for various reaction conditions at 0.2, 0.5 and 0.8 solvent fractions. Thus obtained kpd0 and ktd0 kinetic parameters were extrapolated to zero solvent fractions and from obtained values of kinetic parameters the conversion points for bulk DAT polymerization were calculated and compared to measured conversion points.

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