scholarly journals Estimation of Electrode Kinetic Parameters of the Lithium/Thionyl Chloride Cell Using a Mathematical Model

1989 ◽  
Vol 136 (10) ◽  
pp. 2798-2805 ◽  
Author(s):  
T. I. Evans ◽  
R. E. White
Keyword(s):  
Mathematical Model ◽  
Kinetic Parameters ◽  
Thionyl Chloride ◽  
Chloride Cell

Kinetic modelling of microalgal growth and fucoxanthin synthesis in photobioreactor

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Xiaojuan Zhang ◽  
Junru Zhao ◽  
Jie Zhang ◽  
Shijing Su ◽  
Luqiang Huang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Kinetic Parameters ◽  
Kinetic Modelling ◽  
Inhibitory Effect ◽  
Rate Equations ◽  
Phosphorus Concentration ◽  
Model Output ◽  
Nitrogen And Phosphorus ◽  
Nitrogen Phosphorus

Abstract This paper presented a mathematical model to describe the production of fucoxanthin by alga Thalassiosira weissflogi ND-8 in photobioreactor. Our interest was focused on characterizing the effects of nitrogen and phosphorus on the growth of microalgae and on the synthesis of fucoxanthin. The rate equations of microalgal growth, fucoxanthin synthesis and substrate consumptions were formulated. Kinetic parameters of the model and their sensitivities with respect to model output were estimated. The predicted results were compared with experimental data, which showed that this model closely agrees with actual experiment and is able to reflect the growth and metabolism characteristics of microalgae. Our results also indicated that nitrogen plays a major role in the synthesis of fucoxanthin, and the synthesis of fucoxanthin is partially linearly related to the consumption of nitrogen. Phosphorus is primarily consumed in the growth and metabolism of microalgal cells, while excessive phosphorus concentration has an inhibitory effect on the growth of microalgae.

scholarly journals Uptake of cadmium by Pseudokirchneriella supcapitata

2005 ◽  
Vol 48 (6) ◽  
pp. 1027-1034 ◽  
Author(s):  
Magela Paula Casiraghi ◽  
Samuel Luporini ◽  
Eduardo Mendes da Silva
Keyword(s):  
Mathematical Model ◽  
Metal Ions ◽  
Simulation Model ◽  
Kinetic Parameters ◽  
Cellular Membrane ◽  
Surface Absorption ◽  
Fast Absorption ◽  
Passive Adsorption ◽  
Two Stages ◽  
The Mathematical Model

In this work the microalgae Pseudokirchneriella supcapitata was used for the removal of the cadmium in liquids. The accumulations of metal ions by the alga occur in two stages: a very fast absorption (passive adsorption) proceeded by a slower absorption (activate absorption). A mathematical model based on the surface absorption and on the transport into the interior of the cellular membrane was developed. The simulation model kinetic parameters were experimentally obtained. Through the results observed, the mathematical model was shown to be suitable when compared to the experimental results, confirming the validation of the mathematical model.

Development and automation of algorithm for determining basis of nonlinear parameter functions of kinetic constants

2019 ◽  
Vol 19 (4) ◽  
pp. 252-257
Author(s):  
A. S. Ismagilova ◽  
Z. A. Khamidullina ◽  
S. I. Spivak
Keyword(s):  
Mathematical Model ◽  
Kinetic Parameters ◽  
Platinum Catalyst ◽  
Hydrogen Oxidation ◽  
Nonlinear Parameter ◽  
Kinetic Constants ◽  
Model Parameters ◽  
Functional Relations ◽  
The Mathematical Model ◽  
Theoretical Issues

Mathematical modeling of catalytic processes is necessary for the complete and accurate description, as well as for controlling the quality and physicochemical studied of catalysts. In the paper, theoretical issues of industrial catalysis are discussed. The work is devoted to theoretical graph analysis of informativity of kinetic parameters of the model of a complex chemical reaction. The aim is the development and automation of algorithm for determining basis of nonlinear parameter functions in solving inverse problems of chemical kinetics in order to define the number and form of independent combinations of rate constants of elementary stages. A program package for analysis of informativity of kinetic parameters of the mathematical model of a complex catalytic reaction is developed and described. The obtained functional relations between the kinetic parameters can be useful for experimentalists in physicochemical interpretation and analysis of mechanisms of chemical reactions. In other words, the proposed method allows independent combinations of kinetic constants to be distinguished that results in shortening the number of the model parameters and, as a consequence, enhance the accuracy of the mathematical model. The mechanism of hydrogen oxidation over a platinum catalyst is given as an example of the use of the software.

scholarly journals Drug Nanoparticle Stability Assessment Using Isothermal and Nonisothermal Approaches

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Javier Santamaría-Aguirre ◽  
Robert Alcocer-Vallejo ◽  
Mónica López-Fanárraga
Keyword(s):  
Mathematical Model ◽  
Shelf Life ◽  
Kinetic Parameters ◽  
Heterogeneous Systems ◽  
Preexponential Factor ◽  
Storage Conditions ◽  
Isoconversional Method ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Drug Products

Many drugs are administered in the form of liquid-dispersed nanoparticles. Frequently, one of the overlooked aspects in the development of this drug delivery system is the loss of efficacy and the degradation of the carried drugs. Estimating the shelf life of drug products implies the storage of samples under controlled conditions of temperature and humidity for different periods, ranging from months to years, delaying decisions during development, manufacturing, and commercialization. Adapting well-known isothermal and nonisothermal methods to nanoparticles would allow correlating kinetic parameters obtained in a single mathematical model and predicting the shelf life faster than traditional methods. Unlike the traditional approaches, the isoconversional method (i) considers drug products as heterogeneous systems, without a unique kinetic order, (ii) establishes a maximum percentage of degradation, (iii) assumes the same kinetics for all processes regardless of the conditions, and (iv) includes the influence of humidity by a modification of Arrhenius equation. This method serves in calculating the kinetic parameters and shelf life derived from them, in a few weeks. In the same way, nonisothermal treatments allow obtaining these parameters by differential scanning calorimetry. Samples are subjected to different heating rates to establish the temperature at which the thermal decomposition event occurs and, thus, to calculate in a few days the activation energy and the preexponential factor using the Kissinger method. But this approach has limitations: the isoconversional method does not consider crystalline state of the sample, while nonisothermal method ignores the effect of the storage conditions. Processing nanoparticles for isothermal and nonisothermal treatments would allow accurate and fast prediction of the drug-loaded nanoparticle shelf life correlating parameters obtained using a single mathematical model. The accuracy of the prediction would be assessed by comparison of estimated shelf life versus data coming from traditional stability studies.

scholarly journals A Mathematical Model of a Lithium/Thionyl Chloride Primary Cell

1989 ◽  
Vol 136 (2) ◽  
pp. 328-339 ◽  
Author(s):  
T. I. Evans ◽  
T. V. Nguyen ◽  
R. E. White
Keyword(s):  
Mathematical Model ◽  
Thionyl Chloride ◽  
Primary Cell
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