Hetero atoms containing conductive nanocarbon materials are being studied extensively for their electrochemical energy storage and conversion applications. Herein, we report a facile process for the preparation of N-containing carbon/graphene nanocomposites by simultaneous thermal decomposition of polypyrrole into N-containing carbon and reduction of graphene oxide into graphene in H2/Ar atmosphere. The XRD pattern of N-containing carbon/graphene nanocomposites prepared at different temperatures indicated the formation of reduced graphene oxide from the reduction of GO. The FT-IR and Raman spectroscopic analysis revealed the presence of N atoms in the nanocomposites and the elemental analysis was used to estimate the amount of N in the nanocomposite. The XPS analysis distinguished the pyridine, pyrrolic and quaternary forms of N present in the nanocomposite. The slow decomposition of polypyrrole resulted in the mesoporous structure to the resulting nanocomposite, which was confirmed by the BET adsorption–desorption isotherm. The electron microscopic analysis confirmed the presence of highly transparent carbon nanosheets. The amount of N in the nanocomposite that depends on the decomposition temperature was found to influence the electrochemical performance. The nanocomposite prepared at 700 °C showed a large specific capacitance of 296 F/g with an excellent cycling stability of 93% after 1000 cycles.

Purpose: High spatial resolution of Radiochromic gel dosimeter with optical readout system, its tissue equivalence property and ability to map dose distribution in 3D makes it suitable for dosimetric measurements of small fields used in Radiosurgery. Method & Materials: In this work we have used the FX gel and the optical readout system for measuring the beam profiles and the output factors of Radiosurgery circular collimators and micro MLC (mMLC) collimator for 6MV photon beams. The measurements were repeated with GafChromic film and pin‐point ion chamber. FX gels were also irradiated for two Radiosurgery plans, one with arcs using circular collimators and the other with mMLC and static beams. These were compared with the TPS dose distribution. Results: The field size and the FWHM measured with Gel dosimeter were within 1mm for small fields and maximum of 2 mm for 40 cm diameter filed. The beam profile and the penumbra measured with FX gel matched with those measured with GafChromic films. The output factor measured from the optical attenuation coefficient of FX gel and the factors measured with GafChromic film were within 2%. Conclusion: The dose distribution obtained with FX gel was identical to those obtained from the Treatment Planning System