Persistent internal polarization

The above theory reveals that the piezoelectricity of polymer film can be classified into four cases at its origin (A) The intrinsic piezoelectricity due to internal strain in the crystal, (B) the intrinsic piezoelectricity due to strain-dependence of spontaneous polarization, (Q the piezoelectricity originated from the polarization charge qp arising from strain-independent persistent polarization P0, and (D) the piezoelectricity from the true charge gt embedded in the film. It must be emphasized that in cases (Q and (D) heterogeneous strain Au = (u — Sl/T) must exist in the film. 

A similar situation occurs in neurons, where axons and dendrites constitute the polarized domains (C.G. Dotti, 1991). GPI-anchored proteins are endocytosed slowly compared to transmembrane proteins bearing internalization motifs they are also slower to exit the endosomal recycling compartment (S. Chatterjee, 2001). The retention of GPI proteins in endosomes, and the opportunity for the protein to persist in an acidic endosomal... 

According to the theory developed by Wada and Hayakawa the piezoelectric activity in PVDF depends strongly on the magnitude of persistent polarization Ps which originates from a dipole orientation. The piezoelectric eai constant increases proportionally with the Ps. In order to orient the dipoles in form I crystals, it is necessary that the dipoles should be rotated in a main chain by the applied electric field. From this view point, it may be easily understandable that the internal rotation of dipoles more preferentially occurs in the roughly packed crystal lattice than in the closely and thermodynamically stable lattice. This is confirmed by the effect of poling on the intensity of X-ray diffraction. 

The fused carbonate cells operate between 500 and 800°C. In these temperatures the main feature that limits the current density at a given potential is not activation polarization or diffusion current, but the internal resistance of the electrolyte. Another persistent problem is the extreme corrosive nature of the electrolyte, limiting the choice of electrodes to those which resist corrosion, i.e. the noble metal ones. 

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