Abstract-Theisotope separation column process presented in this article represents a space propagation process modeled by second-order quasi-linear equations with two independent variables. The new approach of Cohen's equation using a second-order differential equation in relation to time variable t and spatial variable s is presented. For this stage of development, for variables and there is a limitation of two time constants ( ), or space constants ( ). Also, and evolutions are exponentially increasing, resulting that the phenomenon is cumulative, both in relation to time and in relation to the propagation space. In this case, results a family of curves of the concentration.Index Terms-Isotopic separation process, cohen's equation, transcendent equations, structural parameters approximation.
I. INTRODUCTIONThe space propagation process presented in this article represents an isotope separation column process which is modeled by second-order quasi-linear equations with two independent variables.Using a second-order differential equation in relation with both time and space variables, a new approach of Cohen's equation is presented.In the following equation, it is considered the overdamped version of approximating solutions associated with the isotopic separation phenomena [1]-[3]:(1) For this stage of development, for variables and there is a limitation of two time constants ( ), or space constants ( ). The evolution of and is represented in the following figure:Also, and evolutions are exponentially increasing, resulting that the phenomenon is cumulative, both in relation to time and in relation to the propagation space. In this case, results a family of curves of the concentration.Considering the final values and In addition, it can also be shown that for the decreasing evolutions of and defined by the relations (7) and (8) and exemplified in figure 2, where and , the inflection abscises respectively correspond to those defined in the relations (5) and (6) [1-2].(7) (8) Further, in this paper it will be presented only the case for increasing evolution of the and .Preliminaries of Structural Parameters Approximation Through Transcendence Equations for an Isotope Separation Column Muresan V., Sas D., Clitan I., and Unguresan M.-L.International Journal of Modeling and Optimization, Vol. 7, No. 5, October 2017 305 DOI: 10.7763/IJMO.2017.V7.603 Based on knowing the abscises ( , and ordinate , but also the abscises , and ordinate the aproximating parameters noted above determine the aproximation of both and , respectively and . It will be considered the following transcendentwhere:Calculations start with for providing iterative increasing for until the difference (DIF) changes its mark and fulfills to the solution of the transcendent equation.The following relations corresponds to the approximation of space constants ( ) and ( with an error, as low as the step (At the same time, it can be shown that there is only one value ( for which the curve represented in the following figure passes simultaneously through t...