Systems metastable state

Within this general framework there have been many different systems modelled and the dynamical, statistical prefactors have been calculated. These are detailed in [42]. For a binary mixture, phase separating from an initially metastable state, the work of Langer and Schwartz [48] using die Langer theory [47] gives the micleation rate as... 

The reaction quotient may be measured, at least in principle, for the reacting system at any time. If Z is observed not to change, the system is at equiUbrium, or trapped in a metastable state that serves as a local equiUbrium. In informal work, a time-independent Z is identified directiy with the equiUbrium constant... 

Fig 5 3 Changes in the potential energy of a static mechanical system tell us whether it is in a stable, unstable or metastable state. 

Metastable states are represented on the indicator diagram by the prolongations of the isotherms of homogeneous states beyond the intersections with the line of heterogeneous states. Thus, the productions of the liquid and vapour portions of the isotherm, Fig. 38, meet the heterogeneous parts of the isotherms d2y 03 at Q, P, respectively. At each of these points there are two conditions of existence possible for the system, thus ... 

The dynamic behavior of nonisothermal CSTRs is extremely complex and has received considerable academic study. Systems exist that have only a metastable state and no stable steady states. Included in this class are some chemical oscillators that operate in a reproducible limit cycle about their metastable... 

The agreement shown between calculations and experiment gives eonfidence both in the theoretical method used here, and in the analysis of experimental speetra, in particular in the case of metastable state. Furthermore, the interpretation of the transfer-excitation process is straight forward from the knowledge of the potential energy curves of the collisional system. 

Excitation—The addition of energy to a system, thereby transferring it from its ground state to an excited state. Excitation of a nucleus, an atom, or a molecule can result from absorption of photons or from inelastic collisions with other particles. The excited state of an atom is an unstable or metastable state and will return to ground state by radiation of the excess energy. 

As is well known in calculations of rare events [6, 16, 96], it is notoriously inefficient to start the simulation of trajectories with initial conditions sampled in one of the metastable states. Instead, initial conditions should be sampled at the transition state, which ensures that all trajectories cross the transition state at least once and thereby drastically improves the sampling of reactive events. In the model system (48), such an ensemble is given by... 

Fig. 25 Annealing time evolution of the difference SAXS intensity in the induction period (a) and the crystallization period (b) for the melt crystallization of PET at 244 °C [18]. This system corresponds to crystallization from the metastable state where a nucle-ation and growth type of primary phase separation first occurs followed by the spinodal decomposition type secondary phase separation...

Expression (5.120) means that the relaxation time in an arbitrary symmetrical one-level bistable system is two times smaller than the MFPT T(—d, +d)—that is, two times smaller than the decay time of the metastable state—shown with the dashed line taken into account in Fig. 9. 

As an example, let us consider again a system with a metastable state described by the potential of type II (Fig. 4) [106] (an example with the potential of type I was considered in Ref. 107) ... 

---