in this paper, a non-isothermal two-phase flow in the cathode gas diffusion layer (gdl) of pem fuel cell is modeled. the governing equations including energy, mass and momentum conservation equations are solved by numerical methods. also, the optimal values of the effective parameters such as the electrodes porosity, gas diffusion layer (gdl) thickness and inlet relative humidity are calculated...

We develop a dynamical renormalization method for the problem of local reducibility of analytic linear quasi-periodic skew-product flows on T2×SL(2,R). This approach is based on the continued fraction expansion of the linear base flow and deals with ’small-divisors’ by turning them into ’large-divisors’. We use this method to give a new proof of a normal form theorem for a Brjuno base flow.

This paper presents a software product line architecture where applications are assembled by installing a set of plugins on a common software base. In this architecture, the software base embeds a lightweight workflow engine that guides the main flow of control and data of the application. This architecture eliminates the problem of scattered flow of data and control and facilitates plugin subs...

Skew-product flow which is generated by a nonautonomous recurrent tridiagonal competitive-cooperative system of differential equations is considered. It is shown that any minimal set is an almost 1-1 extension of the base flow and any ω-limit set contains at most two minimal sets, which generalizes the results of J. Smillie [SIAM J. Math. Anal., 15(1984), pp. 530–534] in autonomous cases and H....

Numerical simulations of a model of plane Couette flow focusing on its in-plane spatio-temporal properties are used to study the dynamics of turbulent spots. While the core of a spot is filled with small scale velocity fluctuations, a large scale flow extending far away and occupying the full gap between the driving plates is revealed upon filtering out small scales. It is characterized by stre...

The analysis of grease-lubricaled rolling element bearings i s presented. Exferimen tally determined flow curaes for grease are found to be well correlated by the Herschel-Bdkley model flow eqzration. A theory for predicting roller Jilm thickness based on the assumed flow model i s derived. Experimental results show that grease will deveIop a larger film lhickness lhan the grease base oil at ji...

Numerical simulations of a model of plane Couette flow focusing on its in-plane spatio-temporal properties are used to study the dynamics of turbulent spots. While the core of a spot is filled with small scale velocity fluctuations, a large scale flow extending far away and occupying the full gap between the driving plates is revealed upon filtering out small scales. It is characterized by stre...

Political stock markets (PSM) are sometimes seen as substitutes for opinion polls. On the bases of a behavioral model, specific preconditions were drawn out under which manipulation in PSM can weaken this argument. Evidence for manipulation is reported from the data of two separate PSM during the Berlin 99 state elections. JEL Classification: C93, D4, G1