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Ema Hankić

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Abstract The results of the specific activities of 232Th, 226Ra and 40K measured in samples of commonly used building materials in Bosnia and Herzegovina are presented. Measurements were performed by gamma-ray spectrometer with coaxial HPGe detector. The surface radon exhalation and mass exhalation rates for selected building materials were also measured. The determined values of specific activities were in range from 3.16±0.81 Bq kg−1 to 64.79±6.16 Bq kg−1 for 232Th, from 2.46±0.95 Bq kg−1 to 53.89 ±3.67 Bq kg−1 for 226Ra and from 28.44±7.28 Bq kg−1 to 557.30±93.38 Bq kg−1 for 40K. The radium equivalent activity, the activity concentration index, the external and internal hazard indices as well as the absorbed dose rate in indoor air and the corresponding annual effective dose, due to gamma-ray emission from the radioactive nuclides in the building material, were evaluated in order to assess the radiation hazards for people. The measured specific activities of the natural radioactive nuclides in all investigated building materials were compared with the published results for building materials from other European countries. It can be noted that the results from this study are similar to the data for building materials from neighbouring countries and for building materials used in the EU Member States. The radiological hazard parameters of the building materials were all within the recommended limits for safety use.

Zejnil Tresnjo, Jasmin Adrovic, Ema Hankić

Radon is a unique natural element because it is an inert gas and at the same time radioactive in all of its isotopes. It is known fact that exposure of the population to high concentrations of radon gas leads to irradiation of primarily respiratory organs which can cause lung cancer. Radon is a subject of intense research around the world in order to, among other reasons, assess the risk of exposure and develop appropriate standards of protection and its control. By coal mining and exploitation, radioactive radon gas, which is captured in natural geological structures, is relocated from the deep coal layers. Hence, it is concentrated in the depots and coal seams of the mines or being transported to the surface of the earth where it can significantly change the levels of radioactivity in the working premises and residences. This chapter presents the results of a 3-year research of radon activity concentration and gamma dose rate in the air in underground and surface coal mines of Bosnia and Herzegovina.

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.

The results of activity concentration measurements of natural occurring radioactive nuclides 238U, 235U, 232Th, 226Ra, and 40K in surface soil samples collected in the area of cities Tuzla and Lukavac, northeast region of Bosnia and Herzegovina were presented. Soil sampling was conducted at the localities that are situated in the vicinity of industrial zones of these cities. The measured activity was in the range from (8 ± 4) to (95 ± 28) Bq kg–1 for 238U, from (0.41 ± 0.06) to (4.6 ± 0.7) Bq kg–1 for 235U, from (7 ± 1) to (66 ± 7) Bq kg–1 for 232Th, from (6 ± 1) to (55 ± 6) Bq kg–1 for 226Ra, and from (83 ± 12) to (546 ± 55) Bq kg–1 for 40K. In order to evaluate the radiological hazard of the natural radioactivity for people living near industrial zones, the absorbed dose rate, the annual effective dose and the radium equivalent activity have been calculated and compared with the internationally approved values.

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.

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