NOPR Collection:

Development of a large area telescopic detector system for elastic and transfer reaction angular distribution measurements

2005-08-01T00:00:00Z

Title: Development of a large area telescopic detector system for elastic and transfer reaction angular distribution measurements Authors: Kalita, K; Jhingan, A; Barua, S; Das, J J; Varughese, T; Sugathan, P; Madhavan, N; Nath, S; Verma, S; Singh, R Abstract: A large area telescopic detector set-up (ΔE-E) has been developed for elastic scattering and transfer reaction measurements involving low intensity radioactive ion beam (RIB) at Nuclear Science Centre (NSC), New Delhi. The detector system consists of a transmission type gas ionization chamber (ΔE-E) with axial field geometry followed by E-two-two-dimensional position sensitive silicon detectors (2D-PSSD) placed side by side (50 mm × 50 mm each) for the residual-energy measurements. The gas ionization chamber (IC) gives the energy loss of the particles for Z-identification whereas the silicon detectors give their energy as well as the position. The responses of the IC with alpha and fission sources, and of the entire detector system with ⁷Be beam are presented which demonstrate the overall performance. Page(s): 567-572

Evaluation of excess free volumes and excess internal pressures of binary solutions of o-chlorophenol at different temperatures

2005-08-01T00:00:00Z

Title: Evaluation of excess free volumes and excess internal pressures of binary solutions of o-chlorophenol at different temperatures Authors: Rao, G V Rama; Sarma, A Viswanatha; Ramachandran, D; Rambabu, C Abstract: Ultrasonic velocity, density and viscosity have been measured experimentally and free volume as well as internal pressure and enthalpy were calculated for the binary mixtures of o-chlorophenol with ethyl benzoate, anisic aldehyde and acetonitrile at 303.15, 308.15, 313.15 and 318.15 K over the entire range of composition. Excess values of free volume, internal pressure, enthalpy and Gibb’s free energy of activation have been calculated for these systems. The results were discussed in the light of existing theories of molecular interactions involved and chemical constitution of the liquid components. Page(s): 602-608

CFA-based three input and two outputs voltage-mode universal filter

2005-08-01T00:00:00Z

Title: CFA-based three input and two outputs voltage-mode universal filter Authors: Shah, N A; Rather, M F; Iqbal, S Z Abstract: A new voltage-mode (VM) multifunction filter based on, employing two plus type current feedback amplifiers (CFA) and as many capacitors, and three resistors with three inputs and two outputs, is presented. The proposed configuration synthesize all the generic filtering functions namely lowpass (LP), bandpass (BP), highpass (HP), notch (BS) and allpass (AP) with two functions simultaneously, without requiring the change to be induced in the passive elements and/or rotation of components. The circuit enjoys the features of: orthogonal control of the natural frequency and the quality factor, low impedance outputs suiting cascadibility for higher order transfer functions, and low active and passive sensitivities. The results of computer simulation using PSPICE are discussed. Page(s): 636-639

High field conduction in amorphous thin films of Se₇₀Te₃₀_-xCd_x in dark and in the presence of light

2005-08-01T00:00:00Z

Title: High field conduction in amorphous thin films of Se₇₀Te₃₀_-xCd_x in dark and in the presence of light Authors: Kushwaha, V S; Mehta, N; Kumar, A Abstract: Glassy alloys of Se₇₀Te₃₀_-xCd_x (x = 2, 4, 6) are prepared by the quenching technique. Amorphous thin films of these alloys are prepared by the vacuum evaporation technique. Current–voltage (I-V) characteristics have been studied at various temperatures in the films in dark and in the presence of light. For this purpose, a dc voltage (0 – 300 V) was applied across the film. I-V characteristics show that, at low electric fields, an ohmic behaviour is observed. However, at high electric fields (E ~ 10⁴ V/cm), the current becomes super ohmic. Analysis of the data shows the absence of space charge limited currents in amorphous Se₇₀Te₃₀_-xCd_x thin films as ln I/V versus V curves are not found to be straight lines with high correlation coefficient. Instead, ln I versus V^1/2 curves are found to be straight lines having high correlation coefficient. The slope of these curves decreases with the increase in temperature. A more detailed analysis shows that the dominant mechanism of conduction is of Poole-Frenkel type in dark as well as in the presence of light. Page(s): 630-635

NOPR Collection:

Development of a large area telescopic detector system for elastic and transfer reaction angular distribution measurements

Evaluation of excess free volumes and excess internal pressures of binary solutions of o-chlorophenol at different temperatures

CFA-based three input and two outputs voltage-mode universal filter

High field conduction in amorphous thin films of Se70Te30-xCdx in dark and in the presence of light

High field conduction in amorphous thin films of Se₇₀Te₃₀_-xCd_x in dark and in the presence of light