Browsing Physics (Scholarly Publications) by Author "CHAN, HO-KEI"
Now showing items 1-10 of 10
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Dense packings of spheres in cylinders: Simulations
CHAN, HO-KEI; HUTZLER, STEFAN; WEAIRE, DENIS (2012)We study the optimal packing of hard spheres in an infinitely long cylinder, using simulated annealing, and compare our results with the analogous problem of packing disks on the unrolled surface of a cylinder. The densest ... -
Densest Columnar Structures of Hard Spheres from Sequential Deposition
CHAN, HO-KEI (2011)The rich variety of densest columnar structures of identical hard spheres inside a cylinder can surprisingly be constructed from a simple and computationally fast sequential deposition of cylinder-touching spheres, if the ... -
Effects of Polarization and Permittivity Gradients and Other Parameters on the Anomalous Vertical Shift Behaviour of Graded Ferroelectric Thin Films
CHAN, HO-KEI (2005)We studied theoretically the dependence of the ?polarization offset? on various parameters in compositionally graded ferroelectric thin films. Our model adopts the Landau-Khalatnikov equation to describe hysteresis ... -
Fractal Growth of a Conventional Calamitic Liquid Crystal
CHAN, HO-KEI (2004)We report observation of liquid crystal phase ordering via fractal growth aggregates for a calamitic, non-bent-core mesogen. Fractal growth of a conventional smectic-C (Sm-C) phase from the isotropic melt after a temperature ... -
Growth Laws for the Phase-ordering Dynamics of the B1 Phase of a Bent-core Liquid Crystal
CHAN, HO-KEI (2004)We have experimentally investigated the dynamics of the phase ordering process of bent-core molecules at isothermal conditions, forming the liquid crystalline ?banana? B1 phase from the isotropic melt. In contrast to the ... -
Growth Models of Pure Supercooled Materials
CHAN, HO-KEI (2008)For a pure material, the dynamics of the growth of one phase in a supercooled other phase for the case of a shallow temperature quench is traditionally understood via a kinetic thermal diffusion equation model or ... -
Mechanisms of Imprint Effect on Ferroelectric Thin Films
CHAN, HO-KEI (2005)We have developed a single/double layer model to explain horizontal shifting of measured D-E hysteresis loops (imprint) for ferroelectric thin films. Such phenomenon can be explained by considering three mechanisms or their ... -
Phyllotactic Description of Hard Sphere Packing in Cylindrical Channels
CHAN, HO-KEI; WEAIRE, DENIS (2011)We develop a simple analytical theory that relates dense sphere packings in a cylinder to corresponding disk packings on its surface. It applies for ratios R=D/d (where d and D are the diameters of the hard spheres and the ... -
Theory of Time-dependent Space-charge-limited Conduction
CHAN, HO-KEI (IEEE, 2007)We have developed a theory of timedependent space-charge-limited conduction in recent years to understand a hysteresis-shift phenomenon of graded ferroelectric films. The theory is a generalization of the conventional ... -
Transition from the Exhibition to the Non-exhibition of Negative Differential Thermal Resistance in the Two-segment Frenkel-Kontorova Model
CHAN, HO-KEI (2009)An extensive study of the one-dimensional two-segment Frenkel-Kontorova (FK) model reveals a transition from the counterintuitive existence to the ordinary nonexistence of a negative-differential-thermal-resistance (NDTR) ...