Decay of metastable phase on several types of heterogeneous centers

A system of a metastable phase with several sorts of the heterogeneous centers is considered. An analytical theory for the process of decay in such a system has been constructed. The free energy of formation of the critical embryo is assumed to be known in the macroscopic approach as well as the energy of solvatation. The process is split into some periods and the analytical description of every period is given. The most difficult to describe is the period of the essential formation of the embryos of a new phase. At first some asymptotes are investigated and then a general solution is suggested. Several approximate transformations are accomplished with the corresponding numerical estimates and some analytical justifications.Comment: LATE

Decay on several sorts of heterogeneous centers: Special monodisperse approximation in the situation of strong unsymmetry. 4. Numerical results for the approximation of essential asymptotes

The situation of the metastable phase decay on the several types of heterogeneous centers is considered. This publication directly continues " [email protected] get 0001104 ", " [email protected] get 0001108" and " [email protected] get 0001112 " . In this section the approximation od the essential asymptotes is formulated. This approximation is more simple than the floating monodisperse approximation and the special monodisperse approximation. The evident advantage of this approximation is the absence of the exponential nonlinearity.Comment: LATE

Heterogeneous condensation on several types of centers in dynamic conditions

A system of a metastable phase with several sorts of the heterogeneous centers is considered. An analytical theory for the process of condensation in such a system is constructed in dynamic conditions. The free energy of formation of the critical embryo is assumed to be known in the macroscopic approach as well as the energy of solvatation. The recurrent procedure of the establishing of the characteristic times and lengths is presented. The semiempirical method of the description of the period of essential formation of new phase embryos on the heterogeneous centers of some sort is given.Comment: LATE

Monodisperse approximation in the metastable phase decay

A new simple method for the first order phase transition kinetics is suggested. The metastable phase consumption can be imagined in frames of the modisperse approximation for the distribution of the droplets sizes. In all situations of the metastable phase decay this approximation leads to negligible errors in the total number of droplets appeared in the system. An evident advantage of the presented method is the possibility to investigate the situation of the metastable phase decay on several sorts of heterogeneous centers.Comment: 18 pages LATE

Monodisperse approximation as a tool to determine stochastic effects in decay of metastable phase

Stochastic features of decay of a metastable phase have been investigated with the help of a new monodisperse approximation. This approximation is more precise than the already used one and namely it allows to give a very simple but rather precise way to calculate dispersion of the total droplets number initiated by stochastic appearance of supercritical embryos. The derivation is done for a free molecular regime of droplets growth but the diffusion regime is also discussed.Comment: 19pages, 9 figure

Different approaches in the theory of the metastable phase decay on several types of heterogeneous centers

The situation of the metastable phase decay on the several types of heterogeneous centers is considered. The iteration procedure is formulated and with the help of the avalanche consumption property all iterations can be calculated. The same procedure is done for the monodisperse approximation. Here the avalnche consumption is also used to calculate iterations. It is shown that all iterations with a high number have one and the same structure. It allows to obtain the functional form of solution and to formulate directly an equation on the parameter of this functional form.Comment: LATE

Decay of metastable phase on heterogeneous centers with continuous activity

A system of a metastable phase with a pseudo continuous set of the heterogeneous centers is considered. An analytical theory for kinetics of decay of the metastable phase in such a system is constructed. The free energy of formation of a critical embryo is assumed to be known in the macroscopic approach as well as the solvatation energy. The theory constructed below is based on the quasistationary approximation for the nucleation rate.Comment: LATE

Comment on the "Density profiles in the theory of condensation" (Physica A, 226 (1996) 117-136). Stationary profiles of the condensation

Some simplifications of the theory of the density profiles of condensation are discussed. The role of the additive effects is outlined.Comment: 8 pages, LATE

Kinetics of nucleation under the break of the blow-up growth

Kinetics of the first order phase transition has been investigated. The case when the droplets sizes have a limit value is considered. An analytical theory for such process has been constructed and all main characteristics of the process have been determined by rather simple approximate analytical formulas. The limit for a droplets size violates the avalanche consumption of the mother phase which is the basic feature of the first order phase transition and have been actively used in previous publications. Now one can not state that the main quantity of the already condensated substance is contained in the droplets formed under conditions unperturbed by nucleation process. This requires to introduce some new methods of solutions for kinetic equation which are given in the present paper.Comment: 32 p., Late

Overlapping of the characteristic regions in the decay on heterogeneous centers with equal number density

The situation of the decay of the metastable phase on the several types of heterogeneous centers is described analytically. The total number of heterogeneous centers is supposed to be equal for different types. This description decomposes the general situation into some characterisrtic cases. Every case can be described by some special method. The problem is to show that these characteristic cases cover all possible variants of the composition of the condensation system. This is done is this manuscript. In the first part we consider the general facts which allow to establish this overlapping in principle. In the second part we consider some real model systems and show this overlapping directly by explicit calculations. In the third part we consider the process of nucleation on ions and give the generalization for the centers with a rather arbitrary nature.Comment: LATE