NOPR Community:

Doppler technique for detection of victims buried under earthquake rubble

2014-01-10T16:53:11Z

Title: Doppler technique for detection of victims buried under earthquake rubble Authors: Banerjee, P K; Sengupta, A Abstract: Design and development of an electronic remote victim locator* is described in this paper. It has been designed for locating re motely, any animate subject buried under rubble or behind a barrier. It works on the principle of Doppler effect at microwave frequencies. Electromagnetic signal travel s down the debris from a transmit/receive antenna, illuminates the animate subject under the rubble and returns to the top of the debris having phase modulated with body movements. The antenna picks up the phase-modulated signal , which is processed by a microwave phase synchronous receiver. The detected signal is displayed on an oscilloscope or any other suitable display device. The display is either a regular breathing cycle or any sudden shift in its steady level, resulting from even a slight movement of any part of the body. An important part of the system is the clutter (unwanted reflections) canceller. Presently, the system can penetrate a dry concrete debris depth of about 2 m. Detection depth may be greater if there are more air voids in the debris. Efforts are on to improve the depth of penetration in the rubble. The same system can detect presence of any person behind a barrier, which has security applications. Page(s): 970-974

High input impedance HP, BP and LP filters using FTFNs

2014-01-13T16:52:32Z

Title: High input impedance HP, BP and LP filters using FTFNs Authors: Shah, N A; Malik, M A Abstract: The paper presents a new multi function filter based on and employing four terminal floating nullors(FTFNs) which simultaneously realizes bandpass (BP) and lowpass (LP) filtering functions. The circuit can be made to realize highpass (HP) and bandpass (BP) filtering signals as well by changing one admittance and exhibits high input impedance thus, facilitating cascading of such circuits to realize higher order filters. The circuit employs grounded capacitors which suits contemporary IC design techniques and has the distinct feature of providing controllable gain of all the filtering functions through grounded passive components. Besides enjoying low passive sensitivity figures, the resonance frequency ω₀ and bandwidth ω₀/Q are independently tunable in a sequential manner. PSPICE simulation results are also included. Page(s): 967-969

Fastion transport in P(VDF -HFP)-PMMA-PC-LiClO₄-TiO₂composite gel polymer electrolytes

2014-01-10T16:53:06Z

Title: Fastion transport in P(VDF -HFP)-PMMA-PC-LiClO₄-TiO₂composite gel polymer electrolytes Authors: Saikia, D; Kumar, A Abstract: Thin films or poly (vinylidene fluoride-co-hexafluoropropylene) P(VDF-HFP) and poly (methylmethacrylate) PMMA polymer blend electrolytes plasticized with propylene carbonate (PC) and LiCIO₄ as salt and TiO₂ as inorganic filter have been prepared by solution casting technique. Films of thickness in the range of 30µm- 1 mm prepared by varying the plasticizer-filler and salt-filler ratio were characterized by ac impedance measurements in the temperature range 293-373 K. Addition or ceramic filler to the polymer electrolyte was round to result in an enhancement of the ionic conductivity. A maximum electrical conductivity of ~2.81×10^-2 S/cm at 293 K and ~4.5×10^-2 S/cm at 373 K has been achieved with the dispersion or the TiO2. Transport number measured by Wagner's polarization method, using silver blocking electrodes, was round to be 0.985. FTIR spectral studies confirmed the formation of polymer-salt complex. XRD patterns exhibit the increased amorphicity in the blended composite gel polymer electrolytes. Page(s): 961-966

ESR, optical absorption and transport studies of Cu²⁺ in 50Li₂O₃-(50-x)B₂O₃-xBi₂O₃ glass system

2014-01-10T16:53:03Z

Title: ESR, optical absorption and transport studies of Cu²⁺ in 50Li₂O₃-(50-x)B₂O₃-xBi₂O₃ glass system Authors: Swapna, S Suresh; Chandramouli, V Abstract: The preparation and studies on the spectroscopic and transport properties of lithium bora bismuthate glasses are reported. From IR results, it is observed that at low concentrations, Bi₂O₃ (less than 30 mol %) in the glass acts as glass modifier thereby, increasing non-bridging oxygen ions. At higher concentrations , it enters into the network. The structure of the resulting glass consists of (BiO₃+BO₃) units. The hyperfine splitting in the parallel feature of ESR spectra of Cu²⁺ in the glass is detectable at low concentration of Bi₂O₃, which, however, diminishes at higher concentration o f Bi₂O₃,The ionic conductivity results indicate that, the conductivity is due to the mobile lithium ions and log (electrical conductivity) found to increase with the concentration of bismuth oxide and passes through a maximum at 30 mol % of Bi₂O₃ indicating a mixed glass former effect. Page(s): 954-960

NOPR Community:

Doppler technique for detection of victims buried under earthquake rubble

High input impedance HP, BP and LP filters using FTFNs

Fastion transport in P(VDF -HFP)-PMMA-PC-LiClO4-TiO2 composite gel polymer electrolytes

ESR, optical absorption and transport studies of Cu2+ in 50Li2O3-(50-x)B2O3-xBi2O3 glass system

Fastion transport in P(VDF -HFP)-PMMA-PC-LiClO₄-TiO₂composite gel polymer electrolytes

ESR, optical absorption and transport studies of Cu²⁺ in 50Li₂O₃-(50-x)B₂O₃-xBi₂O₃ glass system