Browsing by Author "A. Naik"

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Development of window for first indian gyrotron
(2009) Subrata Das; Narugopal Nayek; K. Subhadra; Manoj Kandpal; A. Naik; S. Chatterjee; A. Majumdar; M.V. Kartikeyan; A.K. Sinha; P.K. Jain; K. Satyanarayana; JoshiS.N.; A.L. Das
Window happens to be the most critical and vulnerable component in high-power gyrotrons. For the first Indian gyrotron window, a face cooled double sapphire disc structure has been decided for delivering 200 kW power at 42 GHz. Development of sapphire machining and techniques for its UHV grade joining to metals are the major achievements so far. Optimisation of electrical and thermal parameters is in progress. ©2009 IEEE.
Petrographic and geochemical characterization of coals from Tiru valley, Nagaland, NE India
(2012) Prakash Singh; M. Singh; Alok Singh; A. Naik
In Tiru valley region of Mon district coals occur in Barail Formation and are of Oligocene age. This study is the first investigation on the petrographic and geochemical characterization of these coals. These thinly bedded seams (<2 m) need systematic exploration for proper evaluation of the resource.The coals are bright to moderately bright in appearance and at places look moderately dull. The study reveals that Tiru valley coals are sub-bituminous to bituminous-D in rank. The chemical study reveals that these coals are perhydrous in nature with moderately high volatile matter content. The sulphur content was probably increased with pyrite inclusion as the most abundant mineral. Vitrinite is the most dominant maceral group constituting nearly 98% of all the macerals while liptinite and inertinite occur in very low concentration. Facies-critical models used to decipher the paleodepositional environment suggest that these coals evolved under wet moor with moderately high flooding in the paleomire which allowed the sulphate reducing bacteria to thrive.