Cell with Finite Length

This section treats the steady-state behavior of the cell for the case of fixed cell voltage. In the first part, a cell of infinite length is considered. This reduces the problem to the analysis of two ordinary differential equations in space describing the stationary energy balance. The second part deals with a fuel cell of finite length and includes the boundary conditions of Eq. (11) in the investigation. 

The Plate Theory, in whatever form, assumes that the solute is, at all times, in equilibrium with both the mobile and stationary phase. Due to the continuous exchange of solute between the mobile and stationary phases as it progresses down the column, equilibrium between the phases is, in fact, never actually achieved. As a consequence, to develop the Plate Theory, the column is considered to be divided into a number of cells or plates. Each cell is allotted a finite length, and thus, the solute spends a finite time in each cell. The size of the cell is such that the solute is considered to have sufficient time to achieve equilibrium with the two phases. Thus, the smaller the plate, the more efficient the solute exchange between the two phases tn the column and consequently the more plates there are In a given column. This is why the number of Theoretical Plates in a column is termed... 

Similarly to the object representation, the stock sheet with an infinite length and a fixed width was discretized into a finite number of equisized cells of size R R Hence, the stock sheet with the length and the width were characterized by... 

D. R. Franceschetti, J. R. Macdonald, and R. P. Buck [1991] Interpretation of Finite-Length-Warburg-Type Impedances in Supported and Unsupported Electrochemical Cells with Kinetically Reversible Electrodes,... 

Experiments using parallel plate shear, simple as they may be to carry out, cannot be implemented for extended period of time or strain due to the finite length of the shearing surface. One way to overcome this limitation is through simulations with periodic boundary conditions. In experiments, a spatially periodic Couette cell or cyclic shear cell can be used to reduce the effect of confining boundaries and apply a prolonged shear. 

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