An electro-chemo-mechanical analysis of solid oxide fuel cell considering evolution of microstructure in porous electrode using phase-field method

For the numerical simulation of oxygen potential distributions in Solid Oxide Fuel Cell (SOFC), the time-evolution of the anode microstructure is reflected in the macroscopic electrical conductivities and the amount of triple-phase boundaries. Once the oxygen potential distributions are determined, the time-variation of the reduction-induced strains due to nonstoichiometry of oxide materials is calculated along with the thermal strains. These strains cause the macroscopic stresses in mutually constrained components. Thus, the capability of the proposed method is demonstrated in characterizing the aging degradation of the macroscopic electro-chemo-mechanical behavior of SOFC that is caused by the Nisintering in cermet microstructures during long-period control

Phonon-Assisted Stimulated Emission in 2H Type PbI_2(Physics)

The stimulated emission in 2H type PbI_2 crystals has been observed under N_2 laser beam excitation at 4.2 K. The analysis of its gain spectrum shows that the emission is induced by the recombination of free exciton assisted by the emission of one longitudinal optical phonon. At a higher level of excitation, the gain spectrum peak shifts to lower energy side. Possible mechanisms of this spectral change are discussed