Abstract With gamma spectrometric method 23 samples of mineral and thermal waters of Bosnia and Herzegovina were analyzed. Activity concentrations of the investigated radionuclides were in the range 12–346 mBq·L−1 for 40K, 1.1–791 mBq·L−1 for 226Ra, 0.2–221 mBq·L−1 for 228Ra, 13–367 mBq·L−1 for 238U, and 0.6–17 mBq·L−1 for 235U. For all investigated radionuclides annual effective dose was estimated. The estimated total annual committed effective dose received by population as a result of ingestion of water was in the range 0.11–2.51 μSv·y−1 for thermal water and in the range 0.11–38.8 μSv·y−1 for mineral water. Measurement of activity concentrations of natural radionuclides in the examined samples was carried out with a gamma-spectrometer with high-purity germanium (HPGe) detector, having a relative efficiency of 70%.

This document refers to the non-stationary heat conduction through transparent thermal insulators. Non-stationary heat transfer means that temperature varies in time, in all points of the thermal field. Temporal and spatial distributions of the temperature inside of the sample are experimentally determined.

This paper explains passive collection of solar radiation energy using transparent thermal insulators. Transparent thermal insulators are transparent for sunlight, at the same time those are very good thermal insulators. Transparent thermal insulators can be placed instead of standard conventional thermal insulators and additionally transparent insulators can capture solar radiation, transform it into heat and save heat just as standard insulators. Using transparent insulators would lead to reduce in usage of fossil fuels and would help protection of an environment and reduce effects of global warming, etc.