The recent development by Craig (l-3) of an all-glass machine for liquidliquid counter-current fractionation makes possible the application of his method to the separation of porphyrins which cannot readily be separated by the sensitive Willstatter “HCl number” method. In this paper we have studied the application of the Craig method to the separation of a mixture of three known porphyrins, usi...

This paper presents a method for creating and distributing small, precision currents throughout an integrated circuit. The system is designed for use in a bionic cochlear implant. A bandgap reference and an off-chip precision resistor create a single precision reference current. This current is then converted into an oscillation frequency. This oscillation frequency is distributed losslessly ar...

The electrical properties of cervical squamous epithelium have been modelled in the frequency range 100 Hz to 10 MHz. The hierarchical modelling process comprises a cellular level stage, which includes detailed models of cells typical of different depths within the epithelium and a tissue model, which utilizes electrical properties obtained from the cellular models. The fit between the modelled...

Electrical networks provide a natural model to study transport processes such us dielectric breakdown and metal insulator transition in disordered inhomogeneous conductors. We present a calculation for current distribution on an infinite hyper-cubic network due to an external applied current. This is used to compute, analytically, the redistribution of current due to variations in the conductan...

A numerical method was developed for predicting current density distribution in electrochemical systems of several species at steady-state. The fundamental transport equation consisted a partial differential equation (PDE) involving linear terms of diffusion and laminar convection, and nonlinear terms of ionic migration. The boundary conditions (BCs) consisted also PDEs including flux condition...