http://nopr.niscair.res.in/handle/123456789/12729 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/12756 Title: Voltage-mode multifunctional biquadratic filter using single DVCC and minimum number of passive elements <br/> <br/>Authors: Tangsrirat, Worapong; Channumsin, Orapin <br/> <br/>Abstract: A voltage-mode multifunctional biquadratic filter with three input terminals and single output terminal is presented. The proposed circuit is constructed using only one differential voltage current conveyor (DVCC) as active element and minimum number of passive elements, namely two resistors and two capacitors. The circuit can simultaneously realize all five different biquadratic filtering lowpass, bandpass, highpass, bandstop and allpass responses from the same configuration. The non-ideal effects of the presented filter are examined. PSPICE simulations of the proposed circuit are included using 0.35-mm CMOS technology from TSMC. <br/> <br/>Page(s): 703-707 Wed, 28 Sep 2011 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/12755 Title: Hot-pressed nano-composite polymer electrolytes: (1-<i style="">x</i>) [70PEO:30KBrO₃]:<i style="">x</i>SiO₂ <br/> <br/>Authors: Chandra, Angesh; Chandra, Archana; Thakur, S S <br/> <br/>Abstract: The electrical and electrochemical properties of PEO-based hot-pressed nano-composite polymer electrolyte (NCPE) membranes: (1-<i>x</i>) [70PEO:30KBrO₃]:<i>x</i>SiO₂, where <i>x</i> = 0-20 wt. (%), have been studied. NCPE membranes have been casted using a novel hot-press technique in place of the traditional solution cast method. The conventional Solid Polymer Electrolyte (SPE) composition: (70PEO: 30KBrO₃), identified as the highest conducting film at room temperature, has been used as I^st-phase host matrix and nano-size (~8 nm) particles of SiO₂ as II^nd-phase dispersoid. As a consequence of dispersal of SiO₂in SPE host, a conductivity enhancement of an order of magnitude was achieved in NCPE film: [95(70PEO:30KBrO₃):5SiO₂]. This composition has been referred to as Optimum Conducting Composition (OCC). Materials characterization has been done with the help of SEM and DSC techniques. The ion transport behaviour in NCPE membranes have been discussed on the basis of conductivity (σ), mobility (µ), mobile ion concentration (n) and ionic transference number (<i style="">t</i>_ion) studies. The temperature dependent conductivity studies have also been done to compute the activation energy (<i style="">E</i>_a) values by least square linear fitting of ‘logσ-1/<i style="">T</i>’ Arrhenius plots. Thin film solid-state polymeric batteries were fabricated using NCPE OCC as electrolyte and the cell-potential discharge characteristics were studied under different load conditions. <br/> <br/>Page(s): 698-702 Wed, 28 Sep 2011 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/12754 Title: First principles study of electronic, elastic and lattice dynamical properties of Mg₂X (X= Si, Ge and Sn) compounds <br/> <br/>Authors: Pandit, Premlata; Sanyal, Sankar P <br/> <br/>Abstract: First principles pseudopotential method based on density functional theory is used to investigate the structural, electronic, elastic and phonon properties of Mg₂X (X=Si, Ge, Sn) compounds at ambient pressure in antifluorite (anti-CaF₂-type) structure. The calculated lattice parameters, static bulk modulus, its first order pressure derivatives and the elastic constants are compared with available experimental and other theoretical results. All the compounds have shown very small indirect band gap. The linear response method is applied to determine the phonon dispersion relations and phonon density of states. The phonon frequencies of these compounds are compared with Raman frequency to reveal small LO-TO splitting at zone center. <br/> <br/>Page(s): 692-697 Wed, 28 Sep 2011 22:58:59 GMT http://nopr.niscair.res.in/handle/123456789/12753 Title: Microwave absorption in antiferroelectric tin chloride dihydrate crystal <br/> <br/>Authors: Upadhyay, Trilok Chandra; Kumar, Pramod <br/> <br/>Abstract: Two-sublattice pseudospin lattice coupled mode model of Mitsui [<i style="">Phys Rev, </i>111 (1958) 1259] is modified by adding along with third-and-fourth order phonon anharmonic interaction terms for SnCl₂·2H₂O crystal. With the help of double-time thermal Green's function method, expressions for shift, width, renormalized AFE soft mode frequency, Curie temperature, dielectric constant and microwave absorption are obtained for tin chloride dihydrate crystal. By fitting model values of physical quantities, temperature dependence of AFE soft frequency, dielectric constant and microwave absorption have been calculated for tin chloride dihydrate crystal. Theoretical results are compared with experimental results of Mognaschi <i>et al.</i> [<i style="">Phys Rev</i>, B14 (1976) 2005]. <br/> <br/>Page(s): 686-691 Wed, 28 Sep 2011 22:58:59 GMT