Numerical multi-physical optimization of operating condition and current collecting setup for large-area solid oxide fuel cells

Due to the depletion of traditional fossil fuels and the aggravation of related environmental problems,hydrogen energy is gaining more attention all over the world.Solid oxide fuel cell(SOFC)is a promising power generation technology operating on hydrogen with a high efficiency.To further boost the power output of a single cell and thus a single stack,increasing the cell area is an effective route.However,it was recently found that further increasing the effective area of an SOFC single cell with a flat-tubular structure and symmetric double-sided cathodes would result in a lower areal performance.In this work,a multi-physical model is built to study the effect of the effective area on the cell performance.The distribution of different physical fields is systematically analyzed.Optimization of the cell performance is also pursued by systematically tuning the cell operating condition and the current collection setup.An improvement of 42%is revealed by modifying the inlet gas flow rates and by enhancing the current collection.In the future,optimization of cell geometry will be performed to improve the homogeneity of different physical fields and thus to improve the stability of the cell.

Intermediate Temperature Fatigue Induced Precipitation and Associated Corrosion in CrMnFeCoNi High Entropy Alloy

Understanding the corrosion behavior of high entropy alloys(HEAs)after intermediate temperature fatigue is critical to prevent their catastrophic failures from the reduction of corrosion resistance.Here,we investigated the corrosion behavior of CrMnFeCoNi HEA after 500℃ fatigue test with strain amplitudes of 0.2%and 0.5%.The intermediate temperature fatigue induced two types of precipitates,which were determined as Cr-richσphase and NiMn-rich L10 phase.Higher strain amplitude not only promoted precipitates generations but also spread the nucleation sites from intergranular to both intergranular and intragranular.Furthermore,we found that the deterioration in corrosion resistance of the alloy was derived from the increase of precipitates,which destroyed the stability of the passive film.The above results revealed that intermediate temperature fatigue impaired the stabilization of the solid solution state and subsequent corrosion resistance of CrMnFeCoNi HEA,where the higher strain amplitude led to more precipitates and more severe corrosion.

Carbamylated erythropoietin regulates immune responses and promotes long-term kidney allograft survival through activation of PI3K/AKT signaling

Modulation of alloimmune responses is critical to improving transplant outcome and promoting long-term graft survival.To determine mechanisms by which a nonhematopoietic erythropoietin(EPO)derivative,carbamylated EPO(CEPO),regulates innate and adaptive immune cells and affects renal allograft survival,we utilized a rat model of fully MHC-mismatched kidney transplantation.CEPO administration markedly extended the survival time of kidney allografts compared with the transplant alone control group.This therapeutic effect was inhibited when the recipients were given LY294002,a selective inhibitor of the phosphoinositide 3-kinase(PI3K)/protein kinase B(AKT)signaling pathway or anti-EPO receptor(EPOR)antibody,in addition to CEPO.In vitro,CEPO inhibited the differentiation and function of dendritic cells and modulated their production of proinflammatory and anti-inflammatory cytokines,along with activating the PI3K/AKT signaling pathway and increasing EPOR mRNA and protein expression by these innate immune cells.Moreover,after CD4^(+)T cells were exposed to CEPO the Th1/Th2 ratio decreased and the regulatory T cell(Treg)/Th17 ratio increased.These effects were abolished by LY294002 or anti-EPOR antibody,suggesting that CEPO regulates immune responses and promotes kidney allograft survival by activating the PI3K/AKT signaling pathway in an EPOR-dependent manner.The immunomodulatory and specific signaling pathway effects of CEPO identified in this study suggest a potential therapeutic approach to promoting kidney transplant survival.