http://nopr.niscair.res.in/handle/123456789/8200 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/8240 Title: Realization of multi-function biquad filter using operational transconductance amplifier <br/> <br/>Authors: Kumar, K; Pal, K; Gupta, G K <br/> <br/>Abstract: A configuration of voltage mode (VM) multi-function biquad filters (MBF) is presented in this paper. The configuration (MBF) is implemented by using two OTAs (one dual output and other single output) and two capacitors. It realises all standard filtering functions i.e. low pass (LP), high pass (HP), band pass (BP), notch and all pass (AP). This configuration (MBF) can also be constructed using a single OTA, two capacitors and one resistor. It employs minimum of active and passive components and provides an attractive feature in case of BP filter that it can be designed for high Q. In addition, the circuit enjoy low sensitivity performance. The experimental results that confirm the validity of the circuit are included. <br/> <br/>Page(s): 71-74 http://nopr.niscair.res.in/handle/123456789/8239 Title: Surface chemical etching behaviour of pristine and high energy Li ion irradiated kapton-H polyimide <br/> <br/>Authors: Garg, Maneesha; Sharma, Anu; Quamara, J K <br/> <br/>Abstract: <smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="City"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PlaceType"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="PlaceName"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"> High energy heavy ion irradiation effect on surface chemical etching behaviour of kapton-H polyimide has been studied using NaOH (40°C) and NaOCl (55°C) as etchants. The samples have been irradiated with 50 MeV Li ions (fluence 10⁵ ions/cm² at Pelletron Facility, Nuclear Science Center, New Delhi). The etching behaviour is non-linear in NaOH for both pristine and irradiated samples. There is an enhancement in the etching rate in irradiated samples for both NaOH and NaOCl etchants. The etching mechanism of pristine and irradiated kapton-H polyimide with NaOCl and NaOH has been investigated. In irradiated samples the demerization of carbonyl groups, breaking of imide linkages and increase in crystallinity have been held responsible for the change in the etching behaviour. The bulk activation energy of pristine and irradiated samples for NaOH (0.38 and 0.30 eV) and NaOCl (1.6 and 1.3 eV) has been estimated. High temperature vacuum annealed samples when etched with NaOH show swelling instead of etching, which is due to a unique type of gel formation taking place on the surface. </smarttagtype></smarttagtype></smarttagtype></smarttagtype> <br/> <br/>Page(s): 66-70 http://nopr.niscair.res.in/handle/123456789/8238 Title: Dielectric relaxation in glassy Se₇₀Te_30-xAg_x <br/> <br/>Authors: Choudhary, N; Kumar, A <br/> <br/>Abstract: Temperature dependence of dielectric constant (e')and dielectric loss (e") are studied in glassy  Se₇₀Te_30-xAg_xwhere <i style="">x</i> is varied from 0 to 10 in the frequency range 1to 10 kHz and temperature range 300-350 K. The results indicate that the dielectric dispersion exists in the above frequency and temperature range. Loss peaks in  e" versus <i style="">T</i> curve could be observed in ternary Se₇₀Te_30-xAg_x alloys. However, such loss peaks could not be observed in binary Se₇₀Te₃₀ alloy, which indicates that Ag incorporation in binary system, is responsible for such behaviour. This is explained in terms of [(D^-) (Ag⁺)] dipoles which otherwise were not present in the undoped samples. <br/> <br/>Page(s): 62-65 http://nopr.niscair.res.in/handle/123456789/8237 Title: Electronic properties of CdS, CdSe and CdTe semiconductor binary alloys <br/> <br/>Authors: Jivani, A R; Trivedi, H J; Gajjar, P N; Jani, A R <br/> <br/>Abstract: The higher-order perturbation theory based on pseudopotential is used to calculate total energy, band gap at Jones-zone face and bulk modulus of CdS, CdSe and CdTe binary semiconductor compounds. The covalent correction term, which is approximately equal to third and fourth-order perturbation energy, is used in the present study. The ratio of covalent bond correction energy to second-order perturbation energy is about 15% and hence it is essential to study the electronic properties of semiconductor materials. Present theoretical results are found better than other available theoretical findings and good agreements of present finding of total energy, band gap at Jones-zone face and bulk modulus with the experimental data are achieved. <br/> <br/>Page(s): 59-61