To simulate a new economical architecture for PEM fuel cell and investigate the effectiveness of the introduced structure on the performance, computational fluid dynamics (CFD) code is used to solve the equations for a single domain of the cell namely: the flow field, the mass conservation, the energy conservation, the species transport, and the electric/ionic fields under the assumptions of st...

a new retrofit targeting procedure, based on pinch technology has been developed. the new procedure considers existing structure of a given network and finds the most compatible configuration with the network. to achieve this aim, the procedure uses a linear programming technique that maximize the compatibility. good compatibility between old and new networks helps to make the best use of capit...

We describe the Lie bialgebra structure on the Lie superalgebra sl(2, 1) related to an r−matrix that cannot be obtained by a Belavin-Drinfeld type construction. This structure makes sl(2, 1) into the Drinfeld double of a four-dimensional subalgebra. It is well-known that non-degenerate r−matrices (describing quasitriangular Lie bialgebra structures) on simple Lie algebras are classified by Bela...

We give a new structure theorem for subresultants precising their gap structure and derive from it a new algorithm for computing them. If d is a bound on the degrees and τ a bound on the bitsize of the minors extracted from Sylvester matrix, our algorithm has O(d2) arithmetic operations and size of intermediate computations 2τ . The key idea is to precise the relations between the successive Sy...

In the course of our continuing search for novel antimicrobial agents,1-4) we have isolated a novel diketopiperazine, Sch 725418 (1), from culture Micromonospora sp. In this paper, we describe the isolation and structure elucidation of 1 using high resolution ESI-MS and extensive NMR spectroscopic analysis. Fermentation studies of the SP culture 94-00889 were carried out in shake flasks. Stock ...

identification of the factors causing change in policy process plays an important role in implementing healthy policy process. narrative policy framework introduces new concepts and tools to identify the factors causing policy change. one of the important variables in narrative policy framework is narrative structure. narrative structure has so many elements which the main one is plot. plot lin...

in this paper, an innovative mobile platform is presented which is equipped by three new wheels. the core of the new idea is to establish a new design of rigid circular structure which can be implemented as a wheel by variable radius. the structure of wheel includes a circular pattern of a simple two-link mechanism assembled to obtain a wheel shape. each wheel has two degrees of freedom. the fi...