On the extension of CP models to address cathodic protection under a delaminated coating
Cathodic protection models for pipeline and other metallic structures developed to address the presence of coating flaws or holidays do not account explicitly for the presence of a delaminated region surrounding a holiday. The potential drop in the delaminated region was obtained by solving the coupled, non-linear, partial differential, governing equations that describe transport and electrochemical reactions within the delaminated region. The results were used to develop an analytic expression for the potential drop across the delaminated region as a function of delaminated region length and the resistivity of the bulk environment exterior to the holiday. Expressions developed using this approach can be utilized by existing cathodic protection models to deliver improved potential distributions along protected metallic surfaces. The simulations were used to test the commonly employed assumption that transport by diffusion can be neglected in the delaminated region. The influence of diffusion on current was shown to be significant.
Cathodic Protection with Parallel Cylinders
This paper reports that anodes should be placed so as to supply a uniform current density to the surface of the protected cathode to maintain it within a specified potential range relative to the adjacent electrolytic medium. Analysis of two or more parallel circular cylinders is carried out by solving Laplace's equation with the uniform current density on the cathode. The computer is used to sum terms in a solution by separation of variables, and results show the potential variation and average potential drop as functions of the distance of separation. Potential-contour plots compare the extent of significant electric fields for one and for two anodes.
Methods of determining the desired frequency characteristics of the automatic control systems
Considered the methods of determining the desired frequency characteristics of the automatic control systems while the synthesis of their corrective devices.