A new diodicity evaluation criteria, Volumetric Diodicity (Dv), is introduced to analyze the diodicity of NMP (No-Moving-Parts) valves. Recent studies about the valve system are based on the pressure diodicity, defined as the ratio between the pressure drop in forward and reverse flow. However, existing evaluation criteria do not show discrete relationships with actual data. In this paper, an inelastic collision-based analytic turbulent model was designed to approximate the tendency of diodicity by stage number and was verified both experimentally and numerically with CFD (Computational Fluid Dynamics). The new diodicity criterion can be applied in numerous fields that require NMP valves which are operated in relatively low-pressure ranges.
A Study of Transition Metal Substituted Prussian Blue Analogues
The sodium ion battery has limited usage of cathode materials due to its large ionic radii. Prussian Blue Analogues (PBA) have appropriate structure to storage sodium ion but low specific capacity and structural stability cause hardship for commercialization. To solve this problem, It have been preferred to improve the performance by substituting R-site metal. In this study, however, we changed the P-site ion to optimize PBA. we synthesized PBA with 5 different transition metals and the Fe[Co3(CN)6] exhibits a specific capacity of 625mAh/g at 0.1C. Furthermore, the result suggests the tendency between Jahn-Teller effect and reversibiltiy of cells. We believed this work provides the possibility of PBA as cathode materials for sodium ion battery and opens new perspectives for optimizing PBA.