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Petrological and neutron activation analysis of bricks and tiles from York and neighbouring sites with discussion of the analytical and documentary evidence for their production in York up until AD 1750.

We consider the problem of tiling large rectangles using smaller rectangles with the prescribed dimensions 4 x 6 and 5 x 7. Problem B-3 on the 1991 William Lowell Putnam Examination asked "Does there exist a natural number L such that if m and n are integers greater than L, then an m x n rectangle may be expressed as a union of 4 x 6 and 5 x 7 rectangles, any two intersect at most along their boundaries?" Narayan and Schwenk showed in 2002 that all rectangles with length and width at least 34 can be partitioned into 4 x 6 and 5 x 7 rectangles. We investigate necessary and sufficient conditions for an m x n rectangle to be tiled with 4 x 6 and 5 x 7 rectangles. Ashley et al. answered this question for all but 37 cases. We use an integer linear programming approach to eliminate all but five of these cases.

This study researched the history of Space Shuttle Reusable Surface Insulation which was designed and developed for use on the United States Orbiter fleet to protect from the high heating experienced during reentry through Earth's atmosphere. Specifically the tile system which is attached to the structure by the means of an RTV adhesive has experienced situations where the bonds are identified as subnominal. The history of these subnominal conditions is presented along with a recent identification of a subnominal bond between the Strain Isolation Pad and the tile substrate itself. Tests were run to identify the cause of these subnominal conditions and also to show how these conditions were proved to be acceptable for flight. The study also goes into cases that could be used to identify subnominal conditions on tile as a non-destructive test prior to flight. Several options of non-destructive testing were identified and recommendations are given for future research into this topic. A recent topic is also discussed in the instance where gap fillers were identified during the STS-114 mission that did not properly adhere to the substrate. The gap fillers were found protruding past the Outer Mold Line of the vehicle which required an unprecedented spacewalk to remove them to allow for a safe reentry through the atmosphere.