Conference Papers
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Item Benzene hydroxylation to phenol with iron impregnated activated carbon catalysts(Elsevier Inc., 2006) Choi, J.-S.; Kim, T.-H.; Choo, K.-Y.; Sung, J.-S.; Saidutta, M.B.; Badekai Ramachandra, B.R.; Rhee, Y.-W.Iron impregnated on activated carbon was used as catalyst for the direct synthesis of phenol from benzene. The effect of Sn addition to the catalyst was studied. The prepared catalysts were characterized by BET, SEM and XRD analysis. The catalyst 5.0Fe/AC showed good activity in the conversion of benzene and addition of Sn seemed to improve the selectivity of phenol in the reaction. © 2006 Elsevier B.V. All rights reserved.Item MoVW-mixed oxide as a partial oxidation catalyst for methanol to formaldehyde(Elsevier Inc., 2006) Badekai Ramachandra, B.R.; Jung, S.C.; Kim, K.-S.; Choo, K.-Y.; Sung, J.-S.; Kim, T.-H.Mixed oxide with composition Mo0.65V0.25W 0.10Ox was synthesized and its catalytic activity for the selective oxidation of methanol to formaldehyde was investigated. The characterization by scanning electron microscopy, X-ray diffraction, energy dispersive X-ray and Fourier transform infra-red spectroscopy reveals that the prepared catalyst is inhomogeneous nanocrystalline Mo5O 14-type oxide with minor amount of MoO3-type and MoO 2-type material. Thermal activation treatment of the catalyst at 813K resulted in better crystalline sample. The overall structural analysis suggests that the catalytic performance of the MoVW-mixed oxide catalyst in partial oxidation of methanol is related to the formation of the Mo5O 14-type material. © 2006 Elsevier B.V. All rights reserved.Item Ultrafast optical response of a new metal organic complex-polymer composite film(2009) JohnKiran, A.; Lee, H.W.; Kumar, H.C.S.; Rudresha, B.J.; Badekai Ramachandra, B.R.; Yeom, D.-I.; Rotermund, F.A new Cu-based metal organic complex incorporated into poly (methyl mathacrylate) film exhibits large and fast offresonant optical nonlinearity in the 800 to 1550 nm wavelength range. A large x(3) value of l.8 x l0-10 esu is estimated. © 2009 IEEE.Item Ultrafast optical response of a new metal organic complex-polymer composite film(2009) Kiran, A.J.; Lee, H.W.; Kumar, H.C.S.; Rudresha, B.J.; Badekai Ramachandra, B.R.; Yeom, D.-I.; Rotermund, F.A new Cu-based metal organic complex incorporated into poly (methyl mathacrylate) film exhibits large and fast offresonant optical nonlinearity in the 800 to 1550 nm wavelength range. A large Χ(3) value of 1.8×10-10 esu is estimated. © 2009 IEEE.Item Third-order nonlinear optical properties and optical switching of palladium (I) complex(2011) Manjunatha, K.B.; Dileep, R.; Shelar, M.S.; Umesh, G.; Satyanarayan, M.N.; Badekai Ramachandra, B.R.We report the third-order nonlinear optical, optical power limiting and optical switching study of palladium-N-(2-pyridyl)-N′- (5-amino salicylidene) hydrazine triphenylphosphine, using Z-scan technique and pump-probe technique. The measured nonlinear refractive index is n 2=-6.022×10-9esu. The complex exhibits the reverse saturable absorption (RSA), the nonlinear absorption coefficient of β=10.748×10-9m/W. The good optical power limiting and optical switching behavior were observed in this complex. These suggest that this complex is a potential molecule for photonic applications. © 2011 American Institute of Physics.Item Synthesis, characterization and third order nonlinear optical studies of diimine based Zn(II), Cd(II) and Hg(II) complexes(2011) Rudresha, B.J.; Badekai Ramachandra, B.R.; Manjunatha, K.B.; Umesh, G.The Zn(II), Cd(II), Hg(II) complexes bearing diimine and one-dimensional (1D) push-pull NLO-phores with π-conjugation between ligands and metal have been synthesized for two-dimensional (2D) nonlinear optical response. The third-order nonlinear optical properties of complexes were studied using Z-scan technique at 532 nm with nanosecond laser pulses. The complexes show optical limiting behavior. The values of the effective two-photon absorption (2PA) coefficients (β), third-order nonlinear susceptibilities (χ( (3)) and large two-photon absorption cross sections (σ2) are calculated. Z-scan results show that complexes are suitable materials for optical limiting as well as optical switching applications. © 2011 American Institute of Physics.Item Synthesis and third-order nonlinear optical studies of four-coordinated copper(I) complexes(2011) Kumar, H.C.S.; Rudresha, B.J.; Badekai Ramachandra, B.R.; Philip, R.; Guru Row, T.N.G.Three Cu(I) halide complexes [Cu(L)(PPh3)X] (L=1,10- phenanthroline, X=Cl (1), Br (2) and I (3), PPh3=triphenylphosphine) have been synthesised and characterised by spectroscopic techniques. Further structure of the complex 1 was confirmed by single crystal X-ray diffraction analysis. The nonlinear optical properties of the complexes were investigated at 532 nm using single beam Z-scan technique with nanosecond laser pulses. The complexes showed strong optical limiting behavior due to effective three-photon absorption (3PA). The values of 3PA coefficients (γ) for 1, 2 and 3 were found to be 3.2×10-24m3/W2, 6.0×10-25m3/W2 and 1.2×10 -23m3/W2 respectively, which are comparable to good optical limiting materials. These studies demonstrate that the Ligand→copper coordinative bonds facilitate the polarization of the electronic π-system which optimizes the third-order NLO response in the reported complexes. © 2011 American Institute of Physics.Item Mass production of carbon nanofibers on water soluble support(2013) Ravindra, R.; Badekai Ramachandra, B.R.Mass production of carbon nanofibers (CNFs) on a water soluble support has been achieved by chemical vapor deposition method. Carbon nanofibers have been synthesized using metal (Ni, Co, Fe) acetate as catalyst precursors at 680 °C. Upon pyrolysis this catalyst yields metal nanoparticles directly. The sodium chloride was used as catalyst support, it was chosen because of its non toxic and water soluble nature. The problems such as detrimental effect, environment and even cost has been avoided by using water soluble support. The structure of the products was characterized by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy and X-ray diffraction method. The purity of as grown products and purified products was determined by thermal analysis. The yield of CNFs was up to 7500 wt% relative to the nickel catalyst have been achieved in the growth time of 15 mins. The advantage of this synthesis technique is the simplicity and use of easily available low cost precursors. © (2013) Trans Tech Publications, Switzerland.Item Flexible binder free functionalized carbon nanotube electrodes for ultracapacitor(SPIE spie@spie.org, 2014) Badekai Ramachandra, B.R.; Aravinda, L.S.; Bhat, K.U.The Flexible supercapacitor electrode material was prepared by simple spray coating technique. This will provide a greener alternative for the fabrication of binder free composite electrode for supercapacitor applications. A symmetric double layer super capacitor stack was fabricated by using flexible electrodes. The investigation of the capacitance property of the fabricated super capacitor stack was investigated using cyclic voltammetry, chronopotentiometry and electrical impedance spectroscopy studies. The flexible electrode material shows a specific capacitance of 50 Fg-1 with good cyclibility. © 2014 SPIE.Item Enhanced cell adhesion on severe peened-plasma nitrided 316L stainless steel(American Institute of Physics Inc. subs@aip.org, 2018) Jayalakshmi, M.; Badekai Ramachandra, B.R.; Bhat, K.U.Plasma nitriding is an effective technique to enhance the wear resistance of austenitic stainless steels. Recently, severe surface deformation techniques are extensively used prior to nitriding to enhance diffusion kinetics. In the present study, AISI 316L austenitic stainless steel is subjected to peening-nitriding duplex treatment and biocompatibility of treated surfaces is assessed through adhesion of the fibroblast cells. Three-fold increase in the surface microhardness is observed from the un-peened sample to the peened-nitrided sample; with severe peened sample showing intermediate hardness. Similar trend is observed in the number of the fibroblast cells attached to the sample surface. Spreading of some of the fibroblast cells is observed on the sample subjected to duplex treatment; while the other two samples showed only the spindle shaped fibroblasts. Combined influence of surface nanocrystallization and presence of nitride layer is responsible for the improved biocompatibility. © 2018 Author(s).