In cognitive radio networks (CRN), Out-of-Band (OoB) spectrum sensing provides seamless communication. Cognitive radio (CR) users, so called secondary users (SUs), should avoid interference with primary users (PUs), the owner of the licensed band, while trying to access the unused licensed or unlicensed band, for spectrum utilization. When PUs request to access their band, SUs need to vacate th...

The main challenge for light-emitting diodes is to increase the efficiency in the green part of the spectrum. Gallium phosphide (GaP) with the normal cubic crystal structure has an indirect band gap, which severely limits the green emission efficiency. Band structure calculations have predicted a direct band gap for wurtzite GaP. Here, we report the fabrication of GaP nanowires with pure hexago...

Spectrum sharing in open spectrum systems is a challenging problem, particularly since users experience dynamic spectrum availabilities that vary over time and location. In the absence of any centralize infrastructure, users coordinate their spectrum usage to support fair access of spectrum and avoid interference. One critical challenge is to construct an efficient signalling path in the presen...

Cadmium Oxide (CdO) nanoparticles were prepared by precipitation method using Cadmium acetate and ammonia solution. Presence of chemical species, were verified by Fourier Transform Infra Red (FTIR) Spectrum. From X-Ray Diffraction (XRD) spectrum the particle size, d-spacing value and structure of the nanoparticle were analysed. Size of the nanoparticles and the elemental composition were detect...

Cadmium Oxide (CdO) nanoparticles were prepared by precipitation method using Cadmium acetate and ammonia solution. Presence of chemical species, were verified by Fourier Transform Infra Red (FTIR) Spectrum. From X-Ray Diffraction (XRD) spectrum the particle size, d-spacing value and structure of the nanoparticle were analysed. Size of the nanoparticles and the elemental composition were detect...

We propose a new approach to solving the spectrum scarcity problem, called spectrum access scheduling (SAS), which allows heterogeneous wireless systems to share the same spectrum band using protocol engineering methods. SAS treats the collection of wireless systems as an ecosystem, and optimizes the system performance by collaborative designs. The key architectural component in realizing SAS i...

Comet C/1995 O1 (Hale-Bopp) was observed on 27 April 1996 with the ISOPHOT instrument of ISO when it was at 4.6 AU from the Sun. The 2.5–12 m spectrum was recorded at low resolution. We present here the preliminary results of this observation. The 2.5–5 m spectrum shows emission in the CO2 3 band. The CO2 production rate is about 1:3 1028 s 1. The 6–12 m spectrum shows thermal emission at a col...

The new international standard IEEE802.11p (WAVE) defined enhancements to IEEE802.11 (Wi-Fi). A new mobile e-business platform of Wi-Fi and WAVE is described. Based on cognitive radio, the popular wireless network Wi-Fi can collaborate with WAVE in their common unlicensed spectrum band and licensed spectrum band. As a core technology in the cognitive radio field, OFDM is introduced, and a novel...

Localization of matter waves in optical lattices is possible due to the balance of nonlinearity and dispersion which is modified by the band-gap spectrum of matter waves in a periodic potential. Nonlinear localization of a Bose-Einstein condensate with repulsive interatomic interactions loaded into a onedimensional (1D) optical lattice can occur in the form of both bright and dark solitons. Dar...

Copper has many roles in biology that involve the change of coordination sphere and/or oxidation state of the copper ion. Consequently, the study of copper in heterogeneous environments is an important area in biophysics. EPR is a primary technique for the investigation of paramagnetic copper, which is usually the isolated Cu(II) ion, but sometimes as Cu(II) in different oxidation states of mul...