Performance Analysis Techniques for Real-time Broadband RFI Filtering System of uGMRT

Electromagnetic radiation from human activities, known as man-made Radio Frequency Interference (RFI), adversely affects radio astronomy observations. In the vicinity of the Upgraded Giant Metrewave Radio Telescope (uGMRT) array, the sparking on power lines is the major cause of interference at observing frequencies less than 800 MHz. A real-time broadband RFI detection and filtering system is implemented as part of the uGMRT wideband signal processing backend to mitigate the effect of broadband RFI. Performance analysis techniques used for testing and commissioning the system for observations in the beamformer and correlator modes of the uGMRT are presented. The concept and implementation of recording simultaneous unfiltered and filtered data along with data analysis and interpretation is illustrated using an example. For the beamformer mode, spectrogram, single spectral channel, and its Fourier transform is used for performance analysis whereas, in the correlator mode, the cross-correlation function, closure phase, and visibilities from the simultaneously recorded unfiltered and filtered is carried out. These techniques are used for testing the performance of the broadband RFI filter and releasing it for uGMRT users.Comment: 14 pages, 5 figure

Synthesis and Preliminary Evaluation of Some Substituted Pyrazoles as Anticonvulsant Agents

ABSTRACT: A series of 3-[3-(substituted phenyl)-1-isonicotinoyl-1H-pyrazol-5-yl]-2H-chromen-2-one derivatives (4a-k) were synthesized using appropriate synthetic route and characterized by spectral data. The anticonvulsant activity of the synthesized compounds were evaluated against seizure induced by strychnine in mice. All the test compounds were administered at doses of 100 mg/kg body weight. Three compounds of the series, 4b, 4j and 4k exhibited significant anticonvulsant activity comparable to standard drug, phenytoin