Motivated by requirements of freeform architecture, and inspired by the geometry of hexagonal combs in beehives, this paper addresses torsion-free structures aligned with hexagonal meshes. Since repetitive geometry is a very important contribution to the reduction of production costs, we study in detail “honeycomb structures”, which are defined as torsion-free structures where the walls of cell...

In recent years, using directional antennas to reduce the amount of interference and collisions in mobile ad hoc networks has become more and more popular. Due to the problem of broadcast storm caused by flooding route requests, a novel route request flooding approach called Hexagonal Flooding Strategy (HFS) for Ad Hoc networks using directional antennas is introduced in this paper. With direct...

The continuous-time quantum walk (CTQW) on root lattice An ( known as hexagonal lattice for n = 2) and honeycomb one is investigated by using spectral distribution method. To this aim, some association schemes are constructed from abelian group Z⊗n m and two copies of finite hexagonal lattices, such that their underlying graphs tend to root lattice An and honeycomb one, as the size of the under...

The rotordynamic and leaking characteristics of two types of gas damper seals, honeycomb seal and pocket damper seal, were experimentally evaluated on a rotating test rig. The effect of supply pressure, preswirl, and seal eccentricity on seal dynamic performance was investigated in the tests. The pressurized working gas flowed through the seal and exhausted to atmospheric conditions. The maximu...

We study complex-temperature singularities of the Ising model on the triangular and honeycomb lattices. We first discuss the complex-T phases and their boundaries. From exact results, we determine the complex-T singularities in the specific heat and magnetization. For the triangular lattice we discuss the implications of the divergence of the magnetization at the point u = − 3 (where u = z2 = e...

A Dirichlet k-partition of a closed d-dimensional surface is a collection of k pairwise disjoint open subsets such that the sum of their first Laplace-BeltramiDirichlet eigenvalues is minimal. In this paper, we develop a simple and efficient diffusion generated method to compute Dirichlet k-partitions for d-dimensional flat tori and spheres. For the 2d flat torus, for most values of k = 3–9,11,...

The application of low-frequency acoustic methods for nondestructive testing has a very long history, probably originating with a simple tap technique. These techniques have been successfully applied to a variety of materials and are widely used for the assessment of the quality of bonded sheet metals. They have also proved useful in the NDE of composite materials, particularly honeycomb panels...

We study the scattering of waves off a potential step in deformed honeycomb lattices. For deformations below a critical value, perfect Klein tunneling is obtained; i.e., a potential step transmits waves at normal incidence with nonresonant unit-transmission probability. Beyond the critical deformation a gap forms in the spectrum, and a potential step perpendicular to the deformation direction r...

A gas of strongly interacting single-species (spinless) p-orbital fermionic atoms in 2D optical lattices is proposed and studied. Several interesting new features are found. In the Mott limit on a square lattice, the gas is found to be described effectively by an orbital exchange Hamiltonian equivalent to a pseudospin-1/2 XXZ model. For a triangular, honeycomb, or kagome lattice, the orbital ex...

We study theoretically light propagations at the zigzag edge of a honeycomb photonic crystal consisting of dielectric rods in air, analogous to graphene. Within the photonic band gap of the honeycomb photonic crystal, a unimodal edge state may exist with a sharp confinement of optical fields. Its dispersion can be tuned simply by adjusting the radius of the edge rods. For the edge rods with a g...