http://nopr.niscair.res.in/handle/123456789/12003 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/12012 Title: Current/voltage-mode third order quadrature oscillator employing two multiple outputs CCIIs and grounded capacitors <br/> <br/>Authors: Horng, Jiun-Wei <br/> <br/>Abstract: A new quadrature oscillator circuit using two multiple outputs second-generation current conveyors (CCIIs), three grounded capacitors and three resistors is presented. Two high output impedance current-mode signals and two voltage-mode signals each pair with 90° phase difference are available in the proposed circuit. The oscillation condition and oscillation frequency are independently controllable through grounded resistors. The use of only grounded capacitors makes the proposed circuit attractive for integrated circuit implementation. <br/> <br/>Page(s): 494-498 http://nopr.niscair.res.in/handle/123456789/12011 Title: Charge generation and photovoltaic properties of thin film device based on pyronine G:zinc oxide composite <br/> <br/>Authors: Rajkumar; Sharma, G D; Roy, M S <br/> <br/>Abstract: The electrical and photoelectrical properties of thin film hybrid blend device consisting of nanocrystalline inorganic semiconductor zinc oxide (ZnO) and pyronine G (PYR G) (an organic <i>p</i>-type semiconductor) have been studied through recorded fluorescence (FL) spectra, current-voltage characteristics (in dark and under illumination) and photo-action spectra of device. The quenching of FL spectra of PYR G when mixed with ZnO has been interpreted in terms of efficient electron transfer between PYR G (donor) and ZnO (acceptor) on photoexcitation. The observed results justify the formation of bulk heterojunction between PYR G and ZnO, sandwiched between Al and ITO electrodes. The nearly linear dependence of photocurrent with incident light intensity suggests the efficient photo-induced charge-transfer in the device consisting of PYR G:ZnO restricting charge recombination comparatively to device based on pure PYR G. The absorption spectra of the blend suggest the formation of hetero-junction and there is no ground state doping. <br/> <br/>Page(s): 489-493 http://nopr.niscair.res.in/handle/123456789/12010 Title: Role of Sn incorporation in the dielectric properties of Se₇₅Te₂₅ and Se₈₅Te₁₅ glassy alloys <br/> <br/>Authors: Sharma, J; Kumar, S <br/> <br/>Abstract: The effect of Sn incorporation in the dielectric properties of two binary Se-Te glassy systems, comparing the properties of a-Se₇₅Te₂₅, a-Se₈₅Te₁₅ and a-Se₇₅Te₁₅Sn₁₀ glassy alloys, has been studied. The temperature and frequency dependence of the dielectric constants and the dielectric losses in glassy Se₇₅Te_25,Se₈₅Te₁₅and Se₇₅Te₁₅Sn₁₀alloys has been studied by measuring capacitance and dissipation factor in the frequency range 1 kHz-5 MHz and temperature range 300-350 K. A Debye like relaxation of dielectric behaviour has been observed. A detailed analysis shows that the observed dielectric loss is in agreement with the Guintini’s theory of dielectric dispersion based on two electron hopping over a potential barrier and is applicable in the present case. Dielectric constant (<img src='http://www.niscair.res.in/jinfo/epsilon-dash1.gif' border=0>), dielectric loss (<img src='http://www.niscair.res.in/jinfo/epsilon-dash2.gif' border=0>) and loss tangent (tan<img src='/image/spc_char/delta1.gif' border=0>), are found to be highly frequency and temperature dependent. Dependence of these dielectric parameters over the metallic impurity Sn has also been found in the present glassy system. It is observed that <img src='http://www.niscair.res.in/jinfo/epsilon-dash1.gif' border=0>as well as <img src='http://www.niscair.res.in/jinfo/epsilon-dash2.gif' border=0>, both decrease when Sn is incorporated in binary Se₇₅Te₂₅and Se₈₅Te₁₅ glassy systems. The peculiar role of the third element Sn as an impurity is also discussed in terms of electronegativity difference between the elements used in making the aforesaid glassy system. <br/> <br/>Page(s): 483-488 http://nopr.niscair.res.in/handle/123456789/12009 Title: Study of heterogeneous interaction through dielectric properties of binary mixtures of fluorobenzene with methanol <br/> <br/>Authors: Prajapati, A N; Rana, V A; Vyas, A D; Bhatnagar, S P <br/> <br/>Abstract: Complex permittivity of mixtures of fluorobenzene (FB) and methanol (MeOH) over a wide range of concentration (0.0-1.0) has been measured at various temperatures. Vector network analyzer (VNA) operating in the frequency range 0.3 MHz-3.0 GHz is used to obtain complex permittivity spectra of the liquid samples. Complex permittivity of these samples at two spot frequencies 9.1 and 19.61 GHz is also measured using standard microwave benches. Measured values of the dielectric loss (<img src='http://www.niscair.res.in/jinfo/epsilon-dash2.gif' border=0>) have been plotted against dielectric constant (<img src='http://www.niscair.res.in/jinfo/epsilon-dash1.gif' border=0>) in a complex plane for MeOH, FB and their mixtures. Various dielectric parameters like relaxation time (<img src='/image/spc_char/tow.gif' border=0>₀), static dielectric constant (ε₀)and high frequency limiting dielectric constant (<img src='http://www.niscair.res.in/jinfo/infi.gif' border=0>) have been obtained from these curves. Obtained dielectric parameters are used to evaluate Kirkwood correlation factor (<i style="">g</i>), Bruggeman parameter (<i style="">f_B</i>) and thermodynamic parameters. These parameters have been interpreted in terms of molecular interaction between the different molecular species of the liquid mixtures. <br/> <br/>Page(s): 478-482