Self-annealing experiments

The same authors noted that almost 20% of the polyribonucleotides obtained in vitro formed ribonuclease-resistant double-stranded RNA after self-annealing. They concluded that this ribonuclease-resistant RNA arose from partly symmetric transcription and that at most 12-15 of the RNA formed in vitro was complementary to the L strand. The asymmetry of transcription was thought to result from damage of the organelles. These experiments were extended (Aloni and Attardi, 1971). Using HeLa... 

Measurements of the diffusion coefficient under various As-vapour pressures revealed that As self-diffusion was dominated by As self-interstitials. Annealing experiments performed on variously doped samples gave no indication of a Fermi-level effect, and it was concluded that As self-diffusion was governed mainly by neutral defects. The results for As self-diffusion at 900 to llOOC could be described by ... 

In one dimensional diffusion experiments (e.g., starting with a thin film source of A on a B crystal surface) one often finds an exponential decrease in the A concentration at the far tail of the concentration profile. This behavior has been attributed to pipe diffusion along dislocation lines running perpendicular to the surface. Models have been introduced which assume a (constant) pipe radius, rp, inside which Dl = p-D, b and p denoting here bulk and dislocation respectively. P values of 103 have been obtained in this way. It is difficult to assess the validity of these observations. The model considerably simplifies the real situation. During diffusion annealing, the structure of the dislocation networks is likely to change because of self-stress (see Chapter 14) and chemical interactions. 

Despite belief to the contrary, experiments indicate that self-sustained gas-phase combustion is possible in microburners with gaps smaller than 1 mm [28, 29]. Based on the results in Figure 10.8, this can be achieved by making walls as radical quenchless as possible (via appropriate choice of materials and defect elimination by suitable annealing to avoid radical adsorption) and via suitable thermal management (insulation, heat recirculation, etc.). 

Polycrystalline Ceo.77Ndo.230i.885 with a relative density greater than 98%, was prepared and O diffusion experiments were performed at 750 to llOOC under an O partial pressure of 6.6kPa. Concentration profiles of O in the specimens, following diffusion annealing, were measured by means of secondary ion mass spectroscopy. The O self-diffusivity was found to be described by ... 

---