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Iron-decorated polypyrrole-stannic oxide (Fe-PPy-SnO2) nanocomposites were prepared by in situ polymerization. The structural characteristics, morphology, and uniform distribution of SnO2 nanoparticles in iron-decorated PPy-SnO2 nanocomposites were studied by using x-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transfer infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), etc. Also, AC and DC electrical conductivity and electromagnetic shielding interference (EMI) properties were performed. The results revealed that the conductivity increases with a decrease in weight % of SnO2 nanoparticles. It has also been observed that, from 303 K to 378 K, DC conductivity is marginally increased by the increase in temperature. The Fe- PPy-5% SnO2 sample exhibited a marginally lower resistance than that of other composites. The dielectric constant value decreases with the increase in frequency, and the maximum dielectric constant was observed for Fe-PPy-5% SnO2 and the lowest for Fe-PPy-25% SnO2. The Fe-PPy-5% SnO2 sample showed the highest shielding effectiveness as compared to other composites in the frequency range 2–3 GHz. The experimental results show that the materials exhibit useful properties, i.e., EMI shielding properties, and could be developed for different operations in electronic, electrical, and EMI shielding applications. [ABSTRACT FROM AUTHOR]

In this study pin hole dosimeter with deposition based progeny sensors were used to estimate 222Rn, 220Rn and their daughters in the indoor atmosphere. The estimated annual average indoor 222Rn and 220Rn activity concentration were found to be 76.4 Bq m−3 and 93.5 Bq m−3, respectively. The mean value of EEC for radon and thoron was 45.5 Bq m−3 and 1.3 Bq m−3 respectively. The annual effective dose due to indoor 222Rn and 220Rn were found to be 2.9 mSv y−1 and 0.4 mSv y−1 respectively. The estimated effective doses are well below the safe limit as suggested by ICRP for indoor exposure. [ABSTRACT FROM AUTHOR]

Concentrations of radon, thoron and their progeny inside the working place depend on the activity of radionuclides in the soil, building materials, atmospheric conditions, construction of the building, type of work and ventilation condition. Radon is a radioactive noble gas, and it is emanated from 226Ra present in earth crest and building material. Based on the type of work, construction of the building and ventilation condition, concentrations of radon, thoron and their progeny have been measured in 60 workplaces at 10 locations of Mysuru, Bengaluru and Kolar districts of Karnataka state using Solid-State Nuclear Track Detector technique. From the study, variations of radon, thoron and their progeny have been observed with the nature of work. [ABSTRACT FROM AUTHOR]

Human beings are continuously exposed to the radiations coming from terrestrial and extraterrestrial sources and inside their own bodies. This study presents the results of indoor and outdoor ambient gamma dose rates in and around granite regions of Shimoga District, and these measurements were carried out by using environmental radiation Dosimeter ER-709 which is a portable detector. By the measured average absorbed dose rates, annual effective dose (AED) has been calculated by a standard method. Results showed that the indoor and outdoor absorbed dose rates in air of Shimoga district ranged between 114.05 ± 2.11 to 332.6 ± 3.99 nGy/h and 87 ± 1.7 to 276.66 ± 4.76 nGy/h. The indoor and outdoor AED ranged between 0.559 to 1.631 mSv/year with an average value of 0.872 mSv/year and 0.106 to 0.339 mSv/year with an average value of 0.235 mSv/year, respectively. The calculated indoor and outdoor AEDs were found to be higher than the world average. [ABSTRACT FROM AUTHOR]