http://nopr.niscair.res.in/handle/123456789/13448 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/13471 Title: Current-mode universal filter topology with electronic tuning property using single current follower <br/> <br/>Authors: Tangsrirat, Worapong; Bunruang, Kritsada <br/> <br/>Abstract: The current-mode universal biquadratic filter with three inputs and single output (TISO) using single multi-output current followers (MO-CF) has been described. Based on the use of the second-generation current-controlled conveyor working as the MO-CF, the proposed circuit contains only one MO-CF, one resistor and two grounded capacitors, therefore, offers electronic tuning possibilities. It can realize all of the five standard biquadratic filtering functions, all at a high impedance output. The present filter also provides an independent control of the natural angular frequency <img src='http://www.niscair.res.in/jinfo/Omega-knot.gif' border=0> and bandwidth (BW) by adjusting an external <i>dc</i> bias current and has active and passive component sensitivities. <br/> <br/>Page(s): 133-137 http://nopr.niscair.res.in/handle/123456789/13470 Title: Optical study of poly(ethyleneterephthalate) modified by different ionizing radiation dose <br/> <br/>Authors: Aggarwal, P; Dhiman, S; Kumar, G; Scherer, U W; Singla, M L; Srivastava, A <br/> <br/>Abstract: Thin films of poly(ethyleneterephthalate) [PET]were exposed to radiation dose ranging from 10 to 30 kGy by using gamma rays in the range 12.8-177.8 MGy using swift light ions of hydrogen. There was no effect of the radiation dose on the optical behaviour of PET as a result of exposure to radiation dose up to 30 kGy brought about by gamma rays but a significant decrease in the optical band gap values was observed when PET was exposed to swift light ions of hydrogen. The data obtained are discussed in terms of optical studies carried out on PET using swift heavy ions. <br/> <br/>Page(s): 129-132 http://nopr.niscair.res.in/handle/123456789/13469 Title: Preparation and characterisation of yttrium based luminescence phosphors <br/> <br/>Authors: Sivakumar, V; Lakshmanan, Arunachalam; Kumar, R Satheesh; Kalpana, S; Rani, R Sangeetha; Jose, M T <br/> <br/>Abstract: High sensitive Y₂O₃:Eu³⁺, Gd₂O₃:Eu³⁺, (Y_xGd₁_-x)O₃:Eu³⁺, YAG (Y₃Al₅O₁₂):Eu³⁺ and (Y_xGd₁_-x)BO₃:Eu³⁺ luminescence display phosphors have been made by pyrolysis route followed by sintering at a relatively low temperature of 1000°C. The photoluminescent (PL) efficiencies of all the five phosphors under UV excitation are found to be comparable to that of commercial (Y_xGd₁_-x)BO₃:Eu³⁺ (LG make). The PL efficiency as well as 395 nm (4f-4f) to 260 nm (charge transfer) excitation intensity ratio in Y₂O₃:Eu³⁺ was found to vary in a complex way with Eu concentration. YAG:Eu³⁺ could serve as a cheaper substitute to Y₂O₃:Eu³⁺ red phosphor used currently in compact fluorescent lamps. While the PL efficiency of Y₂O₃:Eu³⁺ remains fairly constant with excitation temperature in the region 25-250°C, the PL efficiency of (Y_xGd₁_-x)BO₃:Eu³⁺ gets reduced by more than 30% when the excitation temperature increased from 25 to 250°C. <br/> <br/>Page(s): 123-128 http://nopr.niscair.res.in/handle/123456789/13468 Title: Structural, electrical and optical characterization of CuInS₂ thin films deposited by spray pyrolysis <br/> <br/>Authors: Hussain, K M A; Podder, J; Saha, D K; Ichimura, M <br/> <br/>Abstract: Copper indium disulphide (CuInS₂) thin films have been deposited on glass substrates by varying Cu:In and S:Cu ratios using spray pyrolysis deposition. The structural, compositional and electrical characterizations of the thin films have been analyzed by Energy Dispersive X-ray Analysis (EDAX), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), <i>dc</i> conductivity measurement and UV-VIS-NIR Spectrophotometry. The surface morphology has beenn studied by SEM. From XRD spectrum, the fundamental peaks of CuInS₂ (CIS) thin films have been identified as (112), (004)/(200), (204)/(220), (116)/(312) and (224) which indicate the chalcopyrite structure and showed an improvement of crystallinity of CuInS₂ thin films for Cu:In:S ratio of 1.14:1:1.88. The temperature variation of <i>dc</i> conductivity showed its semiconducting nature in all the films and the highest conductivity was estimated as 11.1786 (<img src='http://www.niscair.res.in/jinfo/omega1.gif' border=0>-cm)^-1 and the corresponding band gap of 1.48eV. <br/> <br/>Page(s): 117-122