Image compression has many applications. For example, it is an important step for distributed and network based pattern recognition. For real time object recognition or reconstruction, image compression can greatly reduce the image size, and hence increase the processing speed and enhance performance. Fractal image compression is a relatively recent image compression method. Its basic idea is t...

Nanocrystals of ZnO were prepared by microwave irradiation using Zn (II) acetate and triethanol amin (TEA) as the starting materials and water as solvent. The nanocrystals of ZnO with hexagonal (Wurtzite) structure were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), UV-Vis absorption and FTIR Spectroscopy techniques.

This thesis is focused on the formation of highly ordered mesoporous structures with adjustable orientation within the ordered, vertical channels of anodic alumina membranes (AAMs) under the conditions of the ‘evaporation-induced self-assembly’ (EISA) method. It is shown that three of the most often used structure directing agents (CTAB, Pluronic123 and Brij56) can be employed for the synthesis...

In this paper, close and open loop hexagonal resonator filter, multiplexer of high selectively and compact size are presented. The tri-band multiplexer topology is based on the hexagonal close loop resonators of different size which capacitive coupled from a single input. The filter and multiplexer have been designed on substrate dielectric constant εr = 10.2 and thickness = 0.635 mm. The hexag...

A single phased Y-type hexagonal ferrite Sr2Co1.7Mg0.3Fe11.2Sn0.4Zn0.4O22 was synthesized by the sol–gel auto combustion method. Structural and magnetic properties of this composition of Y-type hexagonal ferrite have been investigated. The X-ray diffraction (XRD) patterns confirm single phase Y-type hexagonal ferrite and various parameters such as lattice constants and cell volume have been cal...

The existence of Dirac cones in the band structure of two-dimensional materials accompanied by unprecedented electronic properties is considered to be a unique feature of graphene related to its hexagonal symmetry. Here, we present other two-dimensional carbon materials, graphynes, that also possess Dirac cones according to first-principles electronic structure calculations. One of these materi...

Annelid erythrocruorins are extracellular respiratory complexes assembled from 180 subunits into hexagonal bilayers. Cryo-electron microscopic experiments have identified two different architectural classes. In one, designated type I, the vertices of the two hexagonal layers are partially staggered, with one hexagonal layer rotated by about 16 degrees relative to the other layer, whereas in the...

It is shown that it is possible to obtain complete planar phononic bandgaps in square and hexagonal (honeycomb) lattice phononic crystals formed by etching a periodic array of circular holes in a thin silicon plate (or membrane). Also, better bandgap properties are obtained using the hexagonal lattice structure; and, with practical structure sizes, it is possible-to-obtain a gap-to-midgap ratio...

Grazing incidence x-ray-diffraction investigations of the structures of Langmuir-Blodgett films of cadmium behenate with 1, 2, 3, 5, and 21 monolayers are reported. The single monolayer film, deposited on a hydrophilic substrate, showed a hexagonal structure, whereas the bilayer film, deposited on a hydrophobic substrate, had a rectangular structure with herringbone orientation of the acyl chai...