Accelerated growth phase

Accelerated growth phase The cell number starts to increase and the division rate increases to reach a maximum. 

Fig. 6.1 Typical growth curve of unicellular organisms (A) lag phase (B) accelerated growth phase (C) exponential growth phase (D) decelerated growth phase ...

At the end of the lag phase, when growth begins, the division rate increases gradually and reaches a maximum value in the exponential growth period, as shown by the rising inflection at B in Figure 6.1. This transitional period is commonly called the accelerated growth phase and is often included as a part of the lag phase. 

It should be noted that Eq. (6.21) only applies when rx is larger than zero. Therefore, t1 in Eq. (6.21) is not the time that the culture was inoculated, but the time that the cells start to grow, which is the beginning of the accelerated growth phase. 

Accelerated growth phase In this phase, microbes start dividing and new cells will be synthesized. This is an intermittent phase and is found for a relatively short period. 

The maximum rise of number of mobile dislocations in the deformed materials occurs in the range of 10-20 % [9, 10]. Such processes influence on kinetic of phase formation that results in the accelerated growth of s- and y-nitrides and in increase of microhardness of the surface diffusion layers. 

In a well mixed bioreactor a homogeneous suspension exists and typical growth kinetics an be observed as illustrated in Figure 5.17. Six phases can be distinguished the lag phase acceleration phase the exponential growth phase the deceleration phase the stationary phase and the phase at which death/decline occurs. 

In the iirmedlate vicinity of the transition temperature, the free energies of the two phases are equal. The fcriiiatlon of the new phase is caused by fluctuations due to thermal excitation, which moves atoms/Ions to new positions corresponding to the new phase. Subsequent growth Involves the transfer of atoms tc the nuclei by any of the processes listed above. Grain boundaries, dislocation sites, vacancies or other imperfections facilitate diffusion to the nuclei and accelerate sintering/phase transformation [10]. 

Very small nuclei that might form in the gas phase can deposit on the substrate and contribute to heterogeneous deposition and accelerate growth. This accounts for blanket deposition (irrespective of substrate) at high supersaturation and also explains the morphological features of high-temperature deposition discussed below. 

Fig. 1.4.3 Extent of phase separation by spinodal decomposition vs. time showing the various time regimes, starting with the induction period, followed by an accelerated-growth period, then the coarsening period (Redrawn with permission from Caneba and Saxena, 1996)...

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