nano-sized titanium dioxide tio2 powder was prepared by new wet chemical route from its precursor titanium (iv) chloride (ticl4) as precursor with isopropoxy alcohol in presence of nitric acid under ambient condition. their morphologies, phase compositions and components of the tio2 nanoparticles were characterized by transmission electron microscopy (tem), field emission scanning electron micr...

Cognitive Radio Wireless Sensor Networks are emerging technology which provides cognitive capabilities to Wireless Sensor Networks. WSN operates in unlicensed band. Same spectrum band is shared by other wireless devices like Wi-Fi and Bluetooth. Due to this, the unlicensed spectrum is overcrowded which degrades the performance of WSNs. To overcome this issue, Cognitive Radio is integrated with ...

in cognitive radio (CR), CR users or also known as secondary users (SUs) are considered licensed spectrum. During the case when the primary user claims the band of the spectrum that is occupied by the SU ongoing call must be transferred to another unused spectrum band. The variation in spectrum band is called spectrum mobility. In this paper, we investigate an analytical model to show the effec...

With the technological advancement in wireless applications more effective and efficient utilization of the available spectrum became the urgent requirement. According to the IEEE 802.22 standard the unlicensed secondary devices can operate in the licensed TV band, because this is the high underutilized licensed band, so long they do not interfere the licensed primary users. Therefore the secon...

RF spectrum is a scarce resource. It is inefficient when no of users are increased. So cognitive radio is developed for provide to efficient use of bandwidth utilization. Licensed users are primary users and unlicensed users are secondary users. Cognitive radio enables the secondary usage of unused licensed spectrum band. In this Paper, we propose spectrum decision framework for best effort app...

In this research, Germanium-carbon coatings were deposited on ZnS substrates by plasma enhanced chemical vapor deposition (PECVD) using GeH4 and CH4 precursors. Optical parameters of the Ge1-xCx coating such as refractive index, Absorption coefficient, extinction coefficient and band gap were measured by the Swanepoel method based on the transmittance spectrum. The results showed that the refra...

Laser micro-Raman spectroscopy is an ideal tool for assessment and characterization of various types of carbon-based materials. Due to its special optical properties (CrN) coated stainless steel substrates. NCD films have been investigated by laser micro-Raman spectroscopy. The fingerprint of diamond based materials is in the spectral region of 1000-1600 cm-1 in the first order of Raman scatter...