Systematic studies on three dimensionally ordered liquid crystalline phases of different cubic and tetragonal symmetries are presented. The structures of the phases are determined by reconstruction of the electron density distribution from the X-ray diffraction patterns. The known models for electron densities in cubic structures were used whereas a new theoretical model for the structure of th...

Methylammonium lead tri-iodide is a polymorphic material with two temperature-induced phase transitions at 165 K and 327 K, accompanied by an orthorhombic-to-tetragonal and a tetragonal-to-cubic lattice modification. Understanding the origins of these transitions as well as their implications on the crystal structure of the material is fundamental for its technological optimization. Here, we us...

The stability and evolution of ferroelectric domain structures in thin films are studied. Elastic solutions are derived for both elastically anisotropic and isotropic thin films with arbitrary domain structures, subject to the mixed stressfree and constraint boundary conditions. These solutions are employed in a three-dimensional phase-field model to investigate simultaneously the effect of sub...

Superdormant spores of Bacillus subtilis and Bacillus megaterium were isolated in 4 to 12% yields following germination with high nutrient levels that activated one or two germinant receptors. These superdormant spores did not germinate with the initial nutrients or those that stimulated other germinant receptors, and the superdormant spores' defect was not genetic. The superdormant spores did,...

Purified superdormant spores of Bacillus cereus, B. megaterium, and B. subtilis isolated after optimal heat activation of dormant spores and subsequent germination with inosine, d-glucose, or l-valine, respectively, germinate very poorly with the original germinants used to remove dormant spores from spore populations, thus allowing isolation of the superdormant spores, and even with alternate ...

To investigate the primary structural determinants affecting heat resistance of Clostridium sporogenes spores, electron micrographs of heat-sensitive (D121 degrees C = 0.56 min) and heat-resistant (D121 degrees C = 0.93 min) spores of C. sporogenes were taken with a transmission electron microscope. The mean thickness (+/- standard deviation [SD]) of coat layers and cortex regions of heat-sensi...

A lattice metric singularity occurs when unit cells defining two (or more) lattices yield the identical set of unique calculated d-spacings. The minerals Mawsonite and Chatkalite are of especial interest as both are characterized by tetragonal unit cells that correspond to the second member of a quaternary lattice metric singularity. This singularity includes lattices that are Cubic I, Tetragon...

Accurate and efficient traveltime calculation is an important topic in seismic imaging. We present a fast-marching eikonal solver in the tetragonal coordinates (3-D) and trigonal coordinates (2-D), tetragonal (trigonal) fast-marching eikonal solver (TFMES), which can significantly reduce the first-order approximation error without greatly increasing the computational complexity. In the trigonal...