Amorphous and crystalline ices studied by dielectric spectroscopy.

This work reports on frequency dependent ambient-pressure dielectric measurements of hyperquenched glassy water, ice IV, ice VI, as well as a CO-filled clathrate hydrate, the latter featuring a chiral water network. The dipolar time scales and the spectral shapes of the loss spectra of these specimens are mapped out and compared with literature data on low-density and high-density amorphous ices as well as on amorphous solid water. There is a trend that the responses of the more highly dense amorphous ices are slightly more dynamically heterogeneous than those of the lower-density amorphous ices.

Author Correction: Dynamics enhanced by HCl doping triggers 60% Pauling entropy release at the ice XII-XIV transition.

This corrects the article DOI: 10.1038/ncomms8349.

Dynamics enhanced by HCl doping triggers full Pauling entropy release at the ice XII-XIV transition.

The pressure-temperature phase diagram of ice displays a perplexing variety of structurally distinct phases. In the century-long history of scientific research on ice, the proton-ordered ice phases numbered XIII through XV were discovered only recently. Despite considerable effort, none of the transitions leading from the low-temperature ordered ices VIII, IX, XI, XIII, XIV and XV to their high-temperature disordered counterparts were experimentally found to display the full Pauling entropy.

In vivo intrauterine sound pressure and temperature measurements during magnetic resonance imaging (1.5 T) in pregnant ewes.

Objective: To investigate the influence of several magnetic resonance imaging (MRI) sequences on amniotic fluid temperature and intrauterine sound pressure.

Material And Methods: Temperature and sound pressure measurements during MRI (1.5 T) in pregnant ewes were done.