ZnO nanostructures have attracted great attention for possible applications in optoelectronic and spintronic devices. The electrical resistivity because of carriers can be improved by the introduction of Li ions, as Li is a possible dopant for achieving p-type ZnO. We have carried out a comprehensive micro-Raman scattering study of the phonons in 1% Li-and undoped ZnO needle crystals grown and annealed at 1073 K for 1 and 2 h under oxygen environment. Phonon mode of doped and undoped ZnO does not show any measurable shift for the doping concentration of 1%. As line width is related to point defect density, we find for both Li-and undoped ZnO crystals the crystallinity is improving towards the tip of the needle crystals.
In this paper, the convergence aspects of the Extended Kalman Filter, when used as a deterministic observer for a nonlinear discrete-time systems, are addressed and analyzed. The conditions needed to ensure the boundedness of the error covariances which are related to the observability properties of the nonlinear systems are identified through difference equations. Furthermore, boundedness and stability conditions are provided in a noisy environment systems.
Silver nanoparticles of different sizes have been prepared. Absorption spectroscopy reveals the formation of ground state complex. Fluorescence spectroscopy has been used to study the signatures of fluorescence quenching. Properties of N-(2-methylthiophenyl)-2-hydroxy-1-naphthaldimine (NMTHN) on silver nanoparticles has been investigated using optical absorption and fluorescence emission techniques. Quenching of fluorescence of N-(2-methylthiophenyl)-2-hydroxy-1-naphthaldimine has been found to decrease with increase in the size of the silver nanoparticles. The results of the quenching experiments were analyzed through Stern Volmer plot.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.