On the High-Temperature Combustion of n

The combustion of n-butanol has received significant interest in recent years, because of its potential use in transportation applications. Researchers have extensively studied its combustion chemistry, using both experimental and theoretical methods; however, additional work is needed under specific conditions to improve our understanding of n-butanol combustion. In this study, we report new OH time-history data during the high-temperature oxidation of n-butanol behind reflected shock waves over the temperature range of 1300-1550 K and at pressures near 2 atm. These data were obtained at Stanford University, using narrow-line-width ring dye laser absorption of the R1(5) line of OH near 306.7 nm. Measured OH time histories were modeled using comprehensive n-butanol literature mechanisms. It was found that n-butanol unimolecular decomposition rate constants commonly used in chemical kinetic models, as well as those determined from theoretical studies, are unable to predict the data presented herein. Therefore, an improved high-temperature mechanism is presented here, which incorporates recently reported rate constants measured in a single pulse shock tube [C. M. Rosado-Reyes and W. Tsang, J. Phys. Chem. A 2012, 116, 9825-9831]. Discussions are presented on the validity of the proposed mechanism against other literature shock tube experiments. © 2013 American Chemical Society

A poke into the diversity and associations within human anterior nare microbial communities

The anterior nares are the major reservoir for Staphylococcus aureus in humans, where nasal carriage has a crucial function as a source for invasive infections. Despite various investigations on aerobic community members based on traditional cultivation methods, little is known on the overall microbial composition and complex in situ interactions, but such knowledge is highly warranted for effective S. aureus control strategies. As assessed using advanced culture-independent approaches, this study provides a comprehensive survey of the anterior nare bacterial community of 40 individuals. Previously undiscovered co-colonization patterns and natural variations in species composition were revealed and provide insights for future intervention strategies for the control of health-care-and community-associated S. aureus infections