A polynomial algorithm for minimal interval representation

The following problem arises in the context of object representation: given two endpoints of an interval in a Gray code table, find a Boolean function in DNF that represents this interval, with as few prime implicants as possible. This paper shows that there is a unique minimal representation and presents a polynomial algorithm that finds it.     

Short‐lived Phenoxyl Radicals Formed from Green‐Tea Polyphenols and Highly Reactive Oxygen Species: An Investigation by Time‐Resolved EPR Spectroscopy

Polyphenols are effective antioxidants and their behavior has been studied in depth. However, a structural characterization of the species formed immediately upon hydrogen‐atom transfer (HAT), a key reaction of oxidative stress, has not been achieved. The reaction of catechin and green‐tea polyphenols with highly reactive O‐centered H‐abstracting species was studied at the molecular level and in real time by using time‐resolved electron paramagnetic resonance (EPR) spectroscopy. This mirrors the reaction of highly reactive oxygen species with polyphenols. The results show that all phenolic OH groups display essentially identical reactivity. Accordingly, there is no site specificity for HAT and initial antioxidative events are demonstrated to be largely ruled by statistical (entropic) factors.     

Some consequences of the Riemann hypothesis for varieties over finite fields

We deduce from Deligne's form of the Riemann hypothesis and the hard Lefschetz theoremin l-adic cohomology the corresponding facts for any “reasonable” cohomology theory, in particular for crystalline cohomology, and give some applications to algebraic cycles.     

Grain Growth During Superplastic Deformation

Significant grain growth occurring during superplastic deformation is related to the micro-mechanism of superplastic flow. Observations performed on the deformed surface of superplastically deformed tensile and shear Pb-62%Sn samples and bi-axially formed AA7475 samples directly indicate that cooperative grain boundary sliding, i.e. sliding of grain groups, is accompanied by cooperative grain boundary migration that can result in an enhanced grain growth. Such a long range correlation in migration of sliding grain boundaries is related to movement of grain boundary dislocations having a step associated with its core. Observed correlation between grain size and strain measured in different regions of a superplastically formed Ti-alloy part and alignment of grain boundaries along shear surfaces support coupling of grain boundary sliding and migration. A model of grain growth considering climb of cellular dislocations, topological defects in a grain array, has been expanded to incorporate gliding and mixed cellular dislocations.