William J. Porter

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Near-a titanium alloys are used at higher temperatures than any other class of titanium alloys. As a consequence of thermal exposure, these components may develop locally elevated oxygen concentrations at the exposed surface which can negatively impact ductility and resistance to fatigue crack initiation. In this work, monotonic and fatigue fracture(More)
Rutamycin B (2) was synthesized from three principal subunits, spiroketal 75, keto aldehyde 83, and aldehyde 108. First, triol 62 was assembled by Julia coupling of sulfone 56 with aldehyde 58 followed by an acid-catalyzed spiroketalization. The three hydroxyl functions of 62 were successfully differentiated, leading to phosphonate 75. The latter was(More)
The positivity of the probability measure of attractively interacting systems of 2N-component fermions enables the derivation of an exact convexity property for the ground-state energy of such systems. Using analogous arguments, applied to path-integral expressions for the entanglement entropy derived recently, we prove nonperturbative analytic relations(More)
Foreign objects ingested into a gas turbine engine can cause a severe degradation of the fatigue properties of the impacted engine airfoils. Even small objects, such as sand, can cause damage that can reduce the fatigue capability of the material. Several factors have to be considered when evaluating the residual fatigue strength of an impacted material: a)(More)
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