dimensional mathematicalmodel of heat transmission of building structures (in Hungarian)
Hungarian Research Found OTKA
T 038336, 2006.
William S. J.
Engineering heat transfer
, Second Edition, CRC Press, New
intermediate heat exchangers for the MTO process at the initial reaction stage is introduced in this study. A pseudo-homogeneous one-dimensional mathematicalmodel is established and solved by the fourth-order Runge-Kutta integration method. Under the condition
Some possible elementary reactions are not included in the classical mathematical models of thermal decomposition. For example, we can assume that in the thermal decompositions of simple carbonates a proportion of the O2− ions produced on the reaction interface can migrate into the interior of the reactant phase, since at this temperature there is some probability of CO2 exchange between an O2− and a neighbouring CO32− ion. A similar diffusion-type process can be assumed in a wide class of decomposition reactions. The present state of computer science makes it possible to show by mathematical modelling how this migration influences the TG curves of the simplest contracting-sphere-type reactions. The resulting extended contracting-sphere model can provide the induction and the acceleration period of the TG curves.
Authors:A. Rozen, V. Vlasov, V. Marchenko, and V. Rubisov
Progress is reviewed in the authors' works on actinide extraction equilibria (including activity coefficient evaluation from extraction data) and their mathematical modelling (including Tc influence on Pu/U separation).
Authors:B. Anisimov, Yu. Bourmistenko, I. Ivanov, and V. Philippov
A mathematical model is suggested for the approximation of the monoenergetic gamma-ray spectra obtained by a Ge(Li) detector.
Some features of the instrumentation monoline spectra in the energy range upto 2 MeV are considered in detail. Computer program
“APPROXIMATSIYA” is described. The program allows to determine the parameters of the mathematical model with the purpose to
construct a making up standard spectrum library. The results of the monoline spectrum processing are discussed.
Mathematical modeling of toluene oxidation under unsteady state catalyst created by forced oscillations of concentration of
toluene in the reactor inlet was carried out. It is shown that, under periodic reactor operation, the benzaldehyde yield was
up to several times higher than the steady state value. This was explained by the participation of different oxygen species
in the partial and total oxidation on the catalyst surface.
Reading and co-workers introduced a new technique a few years ago called Modulated Differential Scanning Calorimetry or MDSC.
Here the first part of a theoretical analysis for this technique is given. A simple mathematical model for modulated differential
scanning calorimetry in the form of an ordinary differential equation is derived. The model is analysed to find the effect
of a kinetic event in the form of a chemical reaction. Some possible sources of error are discussed. A more sophisticated
version of the model allowing for spatial variation in a calorimeter is developed and it is seen how it can be reduced to
the earlier model. Some preliminary work on a phase change is also presented.
In this paper, pyrolysis characteristics of oil shale obtained from
Huadian, China, are investigated by thermogravimetry method. The effect of
operating conditions, such as particle size, heating rate on the pyrolysis
process is analyzed, and kinetic parameters of pyrolysis at different heating
rates are calculated using a two-stage Arrhenius model that is solved by the
On the basis of these experimental results
and theoretical analysis, a mathematical model, fully suitable for the pyrolysis
characteristics of oil shale, is developed: mass loss rate is described by
a two-stage intrinsic kinetics equation for reducing the calculation error;
pyrolytic heat value of volatile is contained in energy equation, and density
equation is considered as well, due to the release of a large amount of volatiles
in pyrolysis process. Thermogravimetric experimental data are used to validate
the described models.