Browsing by Author "Rao, G.V."

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Effect of CaF2 addition on optical properties of barium phosphate glasses
(2014) Kumar, N.M.; Rao, G.V.; Akhila, B.E.; Shashikala, H.D.
Ternary barium phosphate glasses, (50-X)BaO-XCaF2-50P2O5 have been prepared by adding 0-10 mol% of CaF2 to binary barium phosphate glasses. The amorphous nature of the prepared glasses was confirmed by X-ray diffraction technique. The UV-Visible absorption spectra have been recorded, optical band gap energy Eopt and Urbach energy Etail were determined. Shift in Eopt and Etail with increase in concentration of CaF2 is noted. FTIR analysis was carried out to investigate the short and intermediate-range orders in glasses. Shift of (P-O-P) band to higher wave number with the substitution of BaO with CaF2 shows the shortening of the phosphate chains. Hardness and density of glass samples were measured and correlated with the composition of glasses. � 2014 AIP Publishing LLC.
Optical, dielectric and mechanical properties of silver nanoparticle embedded calcium phosphate glass
(2014) Rao, G.V.; Shashikala, H.D.
Silver nanoparticles have been embedded in 50 mol% CaO-50 mol% P 2O5 glass using melt quenching technique. The quenched glasses were heat treated at 550 C for different durations between 10 and 50 h. The growth of silver nanoparticles in glass matrix appeared to be time dependent. FTIR spectra revealed that silver nanocluster formation had not affected the position of vibration bands of basic phosphate tetrahedral network. The Ag nanoparticle embedded glass matrix showed the red shift and broadening of the surface plasmon resonance (SPR) peak in the visible region with the increase in the duration of the heat treatment. Results showed the increase in size of the nanoparticles in glass matrix with heat treatment which was further confirmed using transmission electron microscopy and XRD. X-ray diffraction studies indicated the presence of Ag crystalline peaks along with amorphous structure on heat treatment at 550 C for 50 h. The dielectric constant of these glasses increased as the duration of the heat treatment increased. Increase in both Vickers hardness and fracture toughness, and decrease in brittleness were observed which can be attributed to the increase in size of the nanoparticles in glass matrix. 2014 Elsevier B.V.
The use of Multi-point Crossover Genetic Algorithm for Clustering the Nodes in WSN
(Institute of Electrical and Electronics Engineers Inc., 2018) Batta, K.B.; Rao, G.V.; Murthy, Y.V.S.
In this work, an effort has been done on two important objectives of wireless sensor networks (WSNs) such as optimization of the energy consumption and lifetime. Since these two objectives have lot of impact on producing quality services in wireless networks, these two are considered and the solution is identified through clustering based models. Cluster information is maintained with the as it is appropriate solution for both the objectives. Also, experimentation is done using multi-point crossover genetic algorithm (GA) approach to optimize the time to transmit the information as well as to improvise the life time of a sensor node. Improvised efficiency is found with this effort and the results are compared with existing LEACH and GA using single point crossover techniques. Copy Right Â© INDIACom-2018.