Decomposition of Zn-ferrite for O 2 Generation by Concentrated Solar Radiation

The O2 generation step in two-step water splitting with Zn-ferrite/Zn, Fe3O4 system was studied with a stainless steel reactor having a window of quartz glass plate (Sandwich Reactor) using the 15 kW solar dish concentrator in Australian National University. The reactant flat layer with a small thickness in the Sandwich Reactor was assumed to simulate the flow section of the particle cloud reactor. The temperature of the sample attained 1750 K in a few minutes by concentrated solar radiation, and 40% molar of the Zn-ferrite was decomposed into Fe3O4 to produce Zn0.4Fe 2.6O4, which is the solid solution between ZnFe2O4 and Fe3O4. The laboratory experiment with the Xe beam irradiation showed that the Zn-ferrite decomposition reaction proceeds according to 3/2ZnFe 2O4=3/2Zn + Fe3O4 + O 2. In the solar furnace experiment, the metal Zn vapor produced according to this equation seems to be deposited on the surface of the inner wall of the reactor, or it seems to recombine with the released O 2, converting to ZnO under the condition without quenching system in the present experimental setup

Developing fragility functions for the areas affected by the 2009 Samoa earthquake and tsunami

Fragility functions in terms of flow depth, flow velocity and hydrodynamic force are developed to evaluate structural vulnerability in the areas affected by the 2009 Samoa earthquake and tsunami. First, numerical simulations of tsunami propagation and inundation are conducted to reproduce the features of tsunami inundation. To validate the results, flow depths measured in field surveys and waveforms measured by Deep-ocean Assessment and Reporting of Tsunamis (DART) gauges are utilized. Next, building damage is investigated by visually interpreting changes between pre- and post-tsunami high-resolution satellite images. Finally, the data related to tsunami features and building damage are integrated using Geographic Information System (GIS), and tsunami fragility functions are developed based on the statistical analyses. From the developed fragility functions, we quantitatively understood the vulnerability of a coastal region in American Samoa characterized by steep terrains and ria coasts