Columnar Ice-Crystals

Identification of a Novel “Fishbone” Structure in the Dendritic Growth of Columnar Ice Crystals

Ice crystals growing in highly supersaturated air at temperatures near -5 C exhibit a distinctive, nonplanar dendritic morphology that has not been previously documented or explained. We examine this structure and identify its most prominent features in relation to the ice crystal lattice. Developing a full 3D numerical model that reproduces this robust morphology will be an interesting challen...

Dielectric Investigations on Ferroelectric Columnar Liquid Crystals

Halos and ice crystals

Observing cirrus halos to constrain in-situ measurements of ice crystal size T. J. Garrett, M. B. Kimball, G. G. Mace, and D. G. Baumgardner Department of Meteorology, University of Utah, Salt Lake City, UT, 84112-0110, USA Universidad Nacional Autonoma de Mexico, Mexico City, Mexico Received: 21 December 2006 – Accepted: 16 January 2007 – Published: 26 January 2007 Correspondence to: T. Garret...

Eisenstein Series, Crystals and Ice

Automorphic forms are generalizations of periodic functions; they are functions on a group that are invariant under a discrete subgroup. A natural way to arrange this invariance is by averaging. Eisenstein series are an important class of functions obtained in this way. It is possible to give explicit formulas for their Fourier coefficients. Such formulas can provide clues to deep connections w...

Separated local field spectroscopy of columnar and nematic liquid crystals.

We are in this work comparing the efficiencies of various 1H-13C separated local field (SLF) experiments when applied to columnar and nematic liquid crystals. In particular, the performances of the conventional SLF, proton-detected local field (PDLF), and polarization inversion spin exchange at the magic angle (PISEMA) methods in terms of spectral resolution, robustness, and ability to measure ...