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Numerical models of Solid Oxide Fuel Cells (SOFCs) are important tools in understanding and investigate the effect of design and operation parameters of the SOFC performance and SOFC development works. In this study, one of the clean and highly efficient energy production systems, single tubular anode-supported SOFC is modeled numerically. Mathematical model of the single tubular SOFC is given in terms of the incompressible Navier- Stokes, Knudsen diffusion models, Butler–Volmer kinetic equations and Brinkman equations. For two-dimensional axisymmetric geometry, operating conditions, parameters of fuel cell and governing equations are solved by finite element method software ComsolMultiphysics. Pure H2 89% and H2O 11% are used at anode and air is used at the cathode side as reactant gasses. Temperature, pressure, porosity, permeability and especially distance of current collectors to the cell reactant gas inlet are studied. Optimal cell parameters for this model are determined and reasons of cell performance effects are explained.

Objective: To investigate the protective effect of recombinant human IL-11 (rhIL-11) administered in a systemic manner on retina tissue during ischemia/reperfusion (I/R) injury in a guinea pig model. Materials and Methods: An experimental study in retinal I/R. Placebo, ischemia/sham, ischemia/rhIL-11 groups including five animals in each were formed from male albino guinea pigs. Retinal ischemia was induced by cannulating the anterior chambers and lifting the bottle to a height of 205 cm for 90 Min in the sham and ischemia/rhIL-11 groups. The ischemia/sham and ischemia/rhIL-11 groups received 0.1 cc of a saline solution and 5 μg/kg/day rhIL-11 intraperitoneally one hour before the ischemic insult and during two days of reperfusion, respectively. The guinea pigs were sacrificed for biochemical analysis and the levels of tumor necrosis factor alpha (TNF-α), transforming growth factor beta (TGF-β) and interleukin-6 (IL-6) in retina were analyzed with ELISA. Mann–Whitney-U and Kruskal–Wallis tests were used for statistical analysis. Results: The mean TNF-α level of the sham group was statistically significantly higher than that of the placebo group (p=0.008). The mean TNF-α levels of the placebo and ischemia/rHIL-11 groups were significantly different (p=0.008). The mean retinal TNF-α level of the ischemia/rHIL-11 group was statistically significantly lower than that of the sham group (p=0.008). The mean retinal TGF-β level of the sham group was statistically significantly higher than that of the placebo group (p=0.008). However, the mean retinal TGF-β levels of the placebo and ischemia/rHIL-11 groups were not statistically significantly different (p=0.690). The mean retinal TGF-β level of the ischemia/rHIL-11 group was statistically significantly lower than that of the sham group (p=0.032). The mean retinal IL-6 level of the sham group was significantly higher than that of the placebo group (p=0.008), while there was no statistically significant difference between the placebo group and ischemia/rHIL-11 group for retinal IL-6 levels (p=1.00). The mean retinal IL-6 level of the ischemia/rHIL-11 group was significantly lower than that of the sham group (p=0.008). Conclusion: rhIL-11 treatment reduces the levels of TNF-α, IL-6 and TGF-β in the retina of the ischemia/reperfusion-injured guinea pig retinas.