Secondary containment modes

The Pittsburgh No. 8 semicoke that was cooled from 400 C contained remnant mesophase spheres, and these can be seen in Figure 4. This photomicrograph was taken in the secondary electron mode in the scanning transmission electron microscope. 

In service inspections of French nuclear Pressure Water Reactor (PWR) vessels are carried out automatically in complete immersion from the inside by means of ultrasonic focused probes working in the pulse echo mode. Concern has been expressed about the capabilities of performing non destructive evaluation of the Outer Surface Defects (OSD), i.e. defects located in the vicinity of the outer surface of the inspected components. OSD are insonified by both a "direct" field that passes through the inner surface (water/steel) of the component containing the defect and a "secondary" field reflected from the outer surface. Consequently, the Bscan images, containing the signatures of such defects, are complicated and their interpretation is a difficult task. 

Table 1 contains the metal-to-metal engineering property requirements for Boeing Material Specification (BMS) 5-101, a structural film adhesive for metal to metal and honeycomb sandwich use in areas with normal temperature exposure. The requirements are dominated by shear strength tests. Shear strength is the most critical engineering property for structural adhesives, at least for the simplistic joint analysis that is commonly used for metal-to-metal secondary structure on commercial aircraft. Adhesive Joints are purposefully loaded primarily in shear as opposed to tension or peel modes as adhesives are typically stronger in shear than in Mode I (load normal to the plane of the bond) loading. 

Although the concern is primarily for the response of the piping. system, the possibiliis of dynamic coupling with the containment structure should not be neglected. A concern is whether or not the secondary shield wall will withstand the dynamic interaction between the walls and the pump. This is answered by examining the mode shapes if there were no coupling between the walls and the pump. 

Another frequently encountered problem is that of the solute that contains more than one possible site of secondary interaction. In such cases, one Bj generally dominates the other, and its incorrect identification often leads to incorrect configurational assignment to the solute. Acyclic sulfinate esters, for example, have two potential sites that could serve as B2, the electron pair on sulfur and the alkoxy oxygen. The nonequivalence predictions one would make in choosing either as B2 are different. Solvates 12 and 13 are the two possible solvation modes for t-butyl (/ )-methanesulfinate and an (5 )-carbinol (1). Principal operation of model 12 predicts a highfield... 

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