Interpretation of surface and bulk effects using the pulsed MIS capacitor

The interpretation of lifetimes and surface generation velocities determined from pulsed MIS-C measurements is examined. The effect of surface generation on the C-t response and ‘Zerbst’ plot is demonstrated and values for s₀ are correlated with the density of fast surface states. Different kinds of surface dominated responses are analyzed and we discuss how the bulk characteristics can be retrieved. It is also shown that pulsing from inversion significantly lowers s₀, but for high densities of surface states this technique does not suffice to eliminate surface effects. Finally, an approximate analysis of the C-t data is shown to agree quite well with the more exact analysis and it is then applied to lifetime maps of Si wafers.     

An optical-interference method for experimental stress analysis of cracked structures

An optical interference technique can be used to measure the crack opening in a cracked transparent model of a structure under load. The measured crack opening as a function of distance from the crack tip can be used in conjunction with the opening mode crack tip stress field equations to determine the opening mode stress intensity factor. Application of this method to double cantilever beam specimens comprised of two glass arms bonded together with an epoxy adhesive gave results which were in close agreement with K-calibrations based on compliance measurements. The measuring techniques and the scheme of analyzing the data could be used to obtain K-calibrations of more complex structures.     

On a new method of investigating large technological systems—II Program structure of the network procedure

The present study deals with a digital computer version of the method described in the previous theoretical part. The study describes program structure of the so-called procedure and provides guidance for its practical use. As illustration a problem associated with a chemical plant is disclosed, the size of which demonstrates vividly its performance.     

Linear modelling of multivariable systems with pseudo-random binary input signals

Properties and methods of generation of pseudo-random binary signals are discussed. A theory of linear modelling is developed for multivariable systems in which these signals form the inputs. Modelling with delay operators and exponential weighting function operators is considered. Experimental results are presented to illustrate the theory.