http://nopr.niscair.res.in/handle/123456789/9016 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/9625 Title: <link rel="File-List" href="file:///C:%5CDOCUME%7E1%5Ccharu%5CLOCALS%7E1%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml"> Molecular interactions in binary mixtures of tetrahydrofuran with alkanols (C₆,C₈,C₁₀): An ultrasonic and volumetric study <br/> <br/>Authors: Ali, Anwar; Nain, Anil Kumar; Sharma, Vinod Kumar; Ahmad, Shakil <br/> <br/>Abstract: <link rel="File-List" href="file:///C:%5CDOCUME%7E1%5Ccharu%5CLOCALS%7E1%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml"> The densities and ultrasonic speeds in binary mixtures of tetrahydrofuran (THF) with alkanols (1-hexanol, 1-octanol and 1-decanol) have been measured over the whole composition range at 35 °C. Isentropic compressibility, intermolecular free length, relative association, molecular association, acoustic impedance, excess compressibility, excess molar volume, excess acoustic impedance and excess partial molar volume of alkanols in THF were calculated using the values of density and ultrasonic speed. The variation of these parameters with composition indicates that the disruption of associated structure of alkanols on addition of THF dominates over that of weak interaction between unlike molecules in all the three systems investigated. Moreover, a comparison of theoretical ultrasonic speeds, calculated by using collision factor theory (CFT), free length theory (FLT), Nomoto’s empirical relation and Van Dael-Vangeel’s ideal mixing relation, with those obtained experimentally reveals that CFT, FLT and Nomoto’s relation predict the data well than ideal mixing relation. <br/> <br/>Page(s): 666-673 http://nopr.niscair.res.in/handle/123456789/9624 Title: <link rel="File-List" href="file:///C:%5CDOCUME%7E1%5Ccharu%5CLOCALS%7E1%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml"> Current-mode lowpass, bandpass and highpass biquads using a single current feedback amplifier <br/> <br/>Authors: Shah, N A; Rather, M F; Iqbal, S Z <br/> <br/>Abstract: <link rel="File-List" href="file:///C:%5CDOCUME%7E1%5Ccharu%5CLOCALS%7E1%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml"> A novel current-mode second-order filtering configuration employing an inverting current feedback amplifier (CFA) and four passive elements is presented. The circuit can realize simultaneously lowpass (LP) and bandpass (BP) functions. The circuit supports realisation of highpass (HP) and bandpass (BP) filtering responses as well through RC : CR transformation. All passive sensitivities are low. The circuit has been simulated using Personal Computer-Simulation Programme with Integrated Circuit Emphasis (PSPICE) and simulation results are found to be in close conformity with the theoretical values. <br/> <br/>Page(s): 697-699 http://nopr.niscair.res.in/handle/123456789/9623 Title: Fluorescence quenching of anthracene by aniline in different solvents <br/> <br/>Authors: Reddy, Annoji; Thipperudrappa, J; Biradar, D S; Lagare, M T; Hanagodimath, S M <br/> <br/>Abstract: <link rel="File-List" href="file:///C:%5CDOCUME%7E1%5Ccharu%5CLOCALS%7E1%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml"> Fluorescence quenching of anthracene by aniline in five different solvents has been carried out at room temperature with a view to understand the quenching mechanisms. Experimental results show positive deviation in the Stern-Volmer plots in all the solvents studied. In order to interpret these results the ground state complex and sphere of action static quenching models have been invoked. Using these models various rate parameters have been determined. Ground state complex formation model is found not to be applicable. Using sphere of action static quenching model various rate parameters have been determined. The magnitudes of these parameters imply that sphere of action static quenching model agrees well with the experimental results. Hence, the positive deviation in the S-V plots is attributed to the static and dynamic quenching. Further, with the use of finite sink approximation model it has been observed that these bimolecular reactions are diffusion limited. The dependence of Stern-Volmer constant on dielectric constant of the solvents suggests the charge transfer character of the excited complex. <br/> <br/>Page(s): 648-652 http://nopr.niscair.res.in/handle/123456789/9622 Title: High input impedance allpass networks using four terminal floating nullor <br/> <br/>Authors: Shah, N A; Malik, M A <br/> <br/>Abstract: <link rel="File-List" href="file:///C:%5CDOCUME%7E1%5Ccharu%5CLOCALS%7E1%5CTemp%5Cmsohtml1%5C01%5Cclip_filelist.xml"> Two novel circuits to realize high input impedance voltage-mode allpass filter functions each using a single four terminal floating nullor (FTFN) and four passive components have been presented. The realizibility condition is simple and temperature invariant being in the form of resistor ratio. The phase besides being adjustable by the frequency of applied voltage signal can also be controlled by adjusting the values of passive components without disturbing the realizibility condition. Simulation results are also included. <br/> <br/>Page(s): 700-702