http://nopr.niscair.res.in/handle/123456789/8605 Search the Channel search http://nopr.niscair.res.in/simple-search http://nopr.niscair.res.in/handle/123456789/8709 Title: Time dependence of Lippmann-Schwinger states <br/> <br/>Authors: Dubey, Ritesh Kumar; Menon, V J; Tripathi, D N <br/> <br/>Abstract: Due to the presence of an infinitesimal parameter e in the resolvent, the Lippmann-Schwinger states cannot be strict eigenstates of the Hamiltonian, and their time evolution is very non-trivial (in agreement with Fermi’s golden rule). In sharp contrast, strict Schrödinger eigenstates cannot make transitions into free channels. Artefacts such as adiabatic switching, wave packets, or infinite time span are not needed in our analysis. <br/> <br/>Page(s): 63-66 http://nopr.niscair.res.in/handle/123456789/8708 Title: Electronically tunable current-mode bandpass filter <br/> <br/>Authors: Shah, N A; Iqbal, S Z; Parveen, B <br/> <br/>Abstract: A new current-mode (CM) operational transconductance amplifier-capacitor (OTA-C) structure implementing second-order bandpass (BP) filtering response and offering a variety of performances is presented. The use of one type of sources and grounded capacitors (GC) considerably simplifies the implementation of the filter in contemporary IC form. The electronic tuning of circuit characteristics has been achieved orthogonally by adjusting the transconductance gain (gm) of OTAs. The circuit possesses low sensitivity figures having values less than or equal to unity lending it better performance feature. <br/> <br/>Page(s): 60-62 http://nopr.niscair.res.in/handle/123456789/8707 Title: Blue organic light emitting diode based on lithium tetra-(8-hydroxy-quinolinato) boron complex <br/> <br/>Authors: Kumar, Lokendra; Koireng, R R; Misra, Aparna; Kumar, Pankaj; Dhawan, S K; Kamalasanan, M N; Chandra, Subhas <br/> <br/>Abstract: Blue electro-luminescent materials are essential for the development of full colour display. The synthesis and characterization of blue emitter lithium tetra-(8-hydroxy-quinolinato) boron complex for organic light emitting diode (OLED) applications have been reported. The boron complex was synthesized by the reaction of lithium borohydride with 8-hydroxyquinoline at room temperature and shows absorption cut-off wavelength at 410 nm and bright blue photoluminescence (PL) with a peak wavelength at 485 nm. The electro-luminescence (EL) and <i style="">I</i>-<i style="">V</i> characteristics of bilayer OLED are also reported. The results show that boron complexes have a great potential for the blue emitters for OLED applications.<b style=""></b> <br/> <br/>Page(s): 56-59 http://nopr.niscair.res.in/handle/123456789/8706 Title: Sol-gel processed TiO₂ films on U-shaped glass-rods as optical humidity sensor <br/> <br/>Authors: Yadav, B C; Shukla, R K; Bali, L M <br/> <br/>Abstract: The fabrication and characterization of a thick-film optical humidity sensor based on the semiconducting metal-oxide TiO₂ have been described_.The sensor element consists of a thin U-shaped borosil glass-rod having different curvature with a film of TiO₂ deposited on it. The films prepared are dried and annealed at 600^oC for two hours, which make them rutile, porous and very sensitive to humidity. Both the ends of the U-shaped glass-rods are coupled to optical fibers. Light from a He-Ne laser is launched in to the sensing element through one of them. Light received from the other fibre is fed into an optical power meter. Variations in the intensity of light with changes in humidity from 5% to 95% have been recorded. <br/> <br/>Page(s): 51-55