More than 2000 tensile and four-point bend tests were made at ambient temperature on specimens from one log of extruded near-isotropic petroleum-coke-based nuclear graphite (Great Lakes Carbon Corporation grade H-451). The mean strengths showed the expected systematic dependence on orientation and location, with axial specimens stronger than radial specimens and material near the edge of the log stronger than material near the centerline. There were additional local fluctuations in strength which, in some cases, corresponded to local variations in density. The coefficient of variation was lower for axial specimens than for radial specimens, and lower for bend specimens than for tensile specimens. The cumulative strength distribution could be fitted equally well by a normal (Gaussian) distribution or by a Weibull distribution. The value of the Weibull modulus, m, was lower for tensile tests than for bend tests, which conflicts with predictions of the Weibull model for the strength of brittle solids. The mean tensile strength of small tensile specimens (volume 724 mm/sup 3/) was higher than that of large tensile specimens (volume 9847 mm/sup 3/) by 3 percent (axial orientation) or 8 percent (radial orientation). These numbers disagree with differences of 28 percent and 38 percent, respectively, predicted by the …

The design and fabrication of a test mask suitable for the experimental evaluation of automated integrated circuit photomask inspection systems is described. This mask contains various types and sizes of intentional defects in known locations. The defects are superimposed on a background of images consisting of a typical integrated circuit pattern.

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, John L. Hill, regarding a legal question submitted for clarification; Whether Cameron County may charge a toll across the county's international bridge.

Some new experiments designed to accurately determine the time interval required to produce a reactive event in confined explosives subjected to temperatures which will cause decomposition are described. Geometry and boundary conditions were both well defined so that these experiments on the rapid thermal decomposition of HE are amenable to predictive modelling. Experiments have been carried out on TNT, TATB and on two plastic-bonded HMX-based high explosives, LX-04 and LX-10. When the results of these experiments are plotted as the logarithm of the time to explosion versus 1/T K (Arrhenius plot), the curves produced are remarkably linear. This is in contradiction to the results obtained by an iterative solution of the Laplace equation for a system with a first order rate heat source. Such calculations produce plots which display considerable curvature. The experiments have also shown that the time to explosion is strongly influenced by the void volume in the containment vessel. Results of the experiments with calculations based on the heat flow equations coupled with first-order models of chemical decomposition are compared. The comparisons demonstrate the need for a more realistic reaction model.