A numerical analysis of an oil-lubricated spiral grooved upstream pumping face seal, accounting for the occurrence of cavitation, have been performed in this paper. The “equivalent flow model”, which is a theoretical scheme for taking the JFO boundary condition into hydrodynamic lubrication theory, was applied to the analyses by a finite difference treatment of the Reynolds equation that dealt with the geometry of logarithmic spiral groove. The calculated results were compared respectively based on Reynolds model and JFO model. The load capacity, cavitation ratio, frictional torque and leakage rate were also theoretically calculated. The difference between the theoretical results based on two boundary conditions for cavitation occurrence is considerable. The JFO boundary condition should be used in theoretical studies on sealing characteristics rather than Reynolds equation, especially in the conditions of less groove depth and high rotary speed.
To calculate the pressure distribution of oil film on spherical port plate of Innas hydraulic transformer (IHT), finite difference method (FDM) based on boundary fitted coordinate (BFC) technique is presented. Spherical curvilinear grid system was obtained with a coincident boundary of irregular physical area. The flux conservation form of Reynolds’ equation was applied as control equation. By FDM, the thickness distribution and pressure distribution of distribution pair were calculated. It shows that BFC transformation method is advantaged to closely simulate the physical domain with complex geometrical boundaries.
Objective:To study the relationship between the levels of B7-H4 and PBC. Methods:Real-time quantitative PCR were used to detect the levels of B7-H4 mRNA on PBMCs. ELISA were used to detect the serum levels of IL-2. FACs were used to detect the CD4+and CD8+ T-lymphocytes frequencies. Results:Levels of B7-H4 mRNA and B7-H4 frequencies were significantly lower than non-PBC hepatic cirrhosis group and healthy controls (P<0.01). After PHA treated for 72h the frequencies of CD4+, CD8+, and CD4+CD8+ T-lymphocytes were all decreased (P<0.05). The same with serum levels of IL-2 (P<0.05). And the frequencies of CD4+ and CD4+CD8+ T-lymphocytes and serum levels of IL-2 were significantly higher in the PBC group than that of non-PBC hepatic cirrhosis group and healthy controls (P<0. 01). Conclusion:Levels of B7-H4 decreased in PBC and could play an important role in immunoregulation of PBC.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.