In this research Fe-TiO2 nanocomposites with different molar ratios of Fe/Ti were prepared as nano-photocatalyst using a modified Sol-Gel process at ambient temperature. Crystallographic properties of nanocomposites were characterized by X-ray Diffraction (XRD). Surface morphology and mean particle size of nanocomposites were specified by Field Emission Scann...

ZnO nanorod was prepared by microwave assisted method. The crystal structure of the nano powders were confirmed by X-Ray diffraction analysis and the mean particle size was estimated by the Scherrer,s formula .The surface morphology of the nano particles were analyzed by   using SEM . The absorption spectrum of the material in the UV-Vis range was recorded .The energy band gap of the...

ZnO nanorod was prepared by microwave assisted method. The crystal structure of the nano powders were confirmed by X-Ray diffraction analysis and the mean particle size was estimated by the Scherrer,s formula .The surface morphology of the nano particles were analyzed by   using SEM . The absorption spectrum of the material in the UV-Vis range was recorded .The energy band gap of the...

Prior knowledge of the spectrum behavior can greatly assist in efficiently performing dynamic spectrum access. This knowledge can be obtained by surveying the spectrum activity, which involves spectrum data collection, primary signal detection, and data analysis. One approach to signal detection is to perform energy detection based on the power measurements. Although considered optimal, this ap...

We calculate the spectrum of three-photon absorption (3PA) in zinc blende semiconductors using Kane's four-band model. We apply this to ZnSe and measure the 3PA spectrum using femtosecond pulses, obtaining excellent agreement. The spectrum shows the apparent onset of 3PA from the split-off band and also shows quantum interference between the several possible evolution pathways when exciting car...

The spectrum utilization is a function of time and location. Hence, at different times and locations the utilization of spectrum might be different. The TV band 52-862 MHz has been the most crucial frequency band in Pakistan that remains unoccupied most of the time. The unoccupied frequency chunks in the TV band are termed as TV White Spaces (TVWS). In this paper, energy detection technique for...

Takashi Kawamura, Hiroshi Shimotahira, Akihito Otani [Summary] Rapid progress in millimeter-wave wireless communication technologies requires accurate spectrum analysis in the frequency domain over 100 GHz. A tunable preselection filter is a key device in building such a spectrum analyzer. This paper proposes a new tunable filter as a preselector in the frequency range from 110 to 140 GHz. The ...

We consider a model of Cournot competition with congestion motivated by recent initiatives in wireless spectrum policy to allow commercial use of spectrum assigned to government agencies. A key feature of such spectrum is that it may be intermittently available due to the incumbent government user’s activity. In our model, wireless Service Providers (SPs) compete for a common pool of customers ...