Pure-rotational spectrometry: a vintage analytical method applied to modern breath analysis.

Pure-rotational spectrometry (PRS) is an established method, typically used to study structures and properties of polar gas-phase molecules, including isotopic and isomeric varieties. PRS has also been used as an analytical tool where it is particularly well suited for detecting or monitoring low-molecular-weight species that are found in exhaled breath. PRS is principally notable for its ultra-high spectral resolution which leads to exceptional specificity to identify molecular compounds in complex mixtures.

Interfacial pinning in the superfluid 3He A-B transition in aerogel.

Continuous-wave NMR studies of 3He in the presence of 99.3% porosity silica aerogel at 34.0 bars and in a magnetic field of 28.

Observation of a superfluid He-3 A- B phase transition in silica aerogel.

New NMR studies of 3He in high-porosity aerogel reveal a phase transition from an A-like to a B-like phase on cooling. The evidence includes frequency shift and magnetic susceptibility data, and similar behavior is found in two quite different aerogel samples. The A-like phase is stable only very near to T(c) but can be supercooled to below 0.