Laboratory experiments to determine the preferred orientation of free-falling hexagonal prisms were performed at Reynolds numbers appropriate to falling ice crystals in the atmosphere. Hexagonal plates orient with their c axis vertical for aspect ratios < 0.9, whilst hexagonal columns fall with their c axis horizontal. A secondary alignment is also observed: regular hexagonal columns fall prefe...

The scattering phase matrices for finite hexagonal cylinders oriented randomly in space were computed by superposing the scattered intensities of Fraunhofer diffracted rays and geometrical optics rays. However, the effect of interference is considered when the optical path lengths for two rays, split by some obstacle and scattered in the same direction, are equal to each other. Single models (c...

The electronic structure of YMnO3 in its highand low-temperature hexagonal phases has been investigated within the local spin-density approximation (LSDA) and by the LSDA + U method which takes into account the local Coulomb interaction between d electrons of transitionmetal ions. In contrast to the case for orthorhombic manganites, the d4-configuration degeneracy is already lifted in the high-...

It has been a significant and challenging issue to derive the complex valid contracted graphs (CGs) with hexagonal links plus other links and identify their isomorphism for creating novel closed mechanisms. This paper focuses on the derivation of the valid CGs with hexagonal links plus other links using the characteristic strings (CSs). First, the concepts on the CGs and CSs are explained, and ...

The behaviour of materials under spatial confinement is sensitively dependent on the nature of the confining boundaries. In two dimensions, confinement within a hard circular boundary inhibits the hexagonal ordering observed in bulk systems at high density. Using colloidal experiments and Monte Carlo simulations, we investigate two model systems of quasi hard discs under circularly symmetric co...

Phase-pure hexagonal and orthorhombic YFeO₃ nanopowders are synthesized by low-temperature solid-state reaction along with Zr doping. The obtained powders are characterized by X-ray diffraction, field emission scanning electron microscopy, and physical property measurements. The hexagonal YFeO₃ exhibits a narrower optical band gap in comparison to the orthorhombic one, while the orthorhombic YF...

Different phases of iron oxide were obtained by hydrothermal treatment of ferric solution at 200°C with the addition of either KOH, ethylenediamine (EDA), or KOH and EDA into the reaction system. As usually observed, the α-Fe2O3 hexagonal plates and hexagonal bipyramids were obtained for reaction with KOH and EDA, respectively. When both KOH and EDA were added into the reaction system, we obser...

The acyl chain of spin-labeled fatty acids intercalates between the lipid hydrocarbon chains in hexagonal and micellar phases with the carboxyl group anchored at the lipid water interface. The spectra are characteristic of anisotropic motion and cannot be distinguished from the spectra of these probes in lamellar dispersions. In the hexagonal and micellar phases the molecular motion of the spin...

Growth of CdS was studied in three different liquid crystalline phases demonstrating the versatility of liquid crystal templating of inorganic solids. Semiconductor growth in a hexagonal liquid crystal yielded a nanostructure with hexagonal symmetry, a lamellar liquid crystal yielded a lamellar nanostructure, and a cubic liquid crystal (consisting of spherical micelles) yielded a hollow, spheri...

When it doesn’t cause confusion, we can omit the sign “·”, e.g. instead of (a · b) · (c · d) we may write ab · cd. In this article, Q will always be a hexagonal quasigroup. The basic example of hexagonal quasigroup is formed by the points of Euclidean plane, with the operation · such that the points a, b and a · b form a positively oriented regular triangle. This structure was used for all the ...