Anomalous Defects and Dynamic Failure of Armor Ceramics

The ballistic performance of state-of-the-art silicon carbide armor material can exhibit a fairly wide variability in certain test configurations, which, it is proposed, may be due to the presence of large (>0.1 mm), rare defects, termed, herein, "anomalous" defects. SiC rubble resulting from ballistic tests was examined, as were quasi-static test samples. Ballistic fragment fracture surfaces revealed large carbonaceous defects that seemed to affect fracture path and mode. Low-strength biaxial flexure samples demonstrated similar defects (>0.1 mm) as failure origins. Carbonaceous defects similar in appearance but smaller in size were also found at the fracture origins of SiC bend bars. Frequently, alumina inclusions were found within the carbonaceous discontinuities. These alumina inclusions may cause the graphitic regions to form during sintering. The random distribution of such large, rare carbonaceous discontinuities from sample-to-sample, as well as batch-to-batch variability, may explain high ballistic variability for SiC armor ceramics.     

Mass Spectra of Some Deuteroethanes

Mass spectra of seven of the nine possible deuteroethanes have been measured. When the patterns are computed on a scale to make the sums of ions equal, it is found that the abundances of molecule ions differ nearly twofold in the different molecules, and there are large differences in the patterns of the two C₂H₄D₂ molecules. The peaks in the C₁ range are compared with the patterns predicted for simple breaking of the C—C bond and dissociation of the methyl radicals. The “weighting factors” for removing H and D, HD, and 2D, etc., from C₂HD₅ are computed and also the weighting factors for H⁺ and D⁺ for all the deuteroethanes are given.     

More on the Wilson Test.

Sheffield (see 33: 132) has presented a conceptually and computationally simplified adaptation of a distribution-free test for analysis of variance hypothesis. The author presents a logical analysis of the technique demonstrating it to be basically unsound. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

PLUGE method of adjusting picture monitors in television studios

The PLUGE method is described, and its advantages are given. Five sets of reference conditions for setting up picture monitors are presented. Further, it is shown that the required PLUGE black level is dependent upon the value of base luminance.     

Dogmatism and acquiescent response set.

"This study was designed to test the hypothesis that Rokeach's Dogmatism Scale [1960], structurally identical to the F scale, is similarily vulnerable to acquiescent response bias." Administration of acquiescent response scales, the F Scale, and the Dogmatism scale to a population of adult neurotics revealed a high intercorrelation, which supports the hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conductivity measurements on cobalt and nickel oxides in highly-enriched oxygen atmospheres

The pressure dependencies of the conductivities of nickel and cobalt monoxides have been investigated in the range 10^–2 to 7.5 × 10² atmospheres at temperatures in the region of 1000° C. Conductivity saturation occurs in CoO due to the formation of Co₃O₄, and the experimental data correlates well with a model for the separation of the higher phase. NiO exhibits no saturation effect in the pressure range investigated and the p^1/5 dependence of the conductivity at 950° C with this oxide above 0.1 atm is interpreted in terms of the formation of singly ionised vacancies.