In this work, we study the effect of concentration, host medium, PH and phase states on the fluorescence emission from the laser dye Rhodamine B pumped by UV laser as exited source. The polymethylmethacrylate PMMA is used as a host medium in case of solid phase samples while, ethanol and Tetrahydrofuran (THF) are used in case of a liquid one. Laser Induced Fluorescence (LIF) technique was used to study the fluorescence properties of both cases of liquid and thin film solid-state samples. In addition, the Dual Thermal Lens (DTL) technique was used to study the quantum yield of these samples. The concentrations of Rhodamine B in ethanol as solvent between 2 x 10(-2) M and 5 x 10(-6) M were studied. The maximum fluorescence emission is observed at concentration of Rhodamine B C = 3 x 10(-4) M. Comparison studies were investigated for different host medium such as ethanol, THF, PMMA in liquid phase state and PMMA in solid phase state. The measurements revealed that, the behavior of both phases state was analogous. Rhodamine B/PMMA thin film sample by ratio of 4:1 and thickness 0.12 mm was found to have the best photostability sample with a quantum yield about approximately 0.82.

Radon-222 exhalation from different ceramic tiles depends upon the radium ( 226 Ra) concentration and porosity. Raw zirconium sand is one of the substances widely used in the ceramic industry and it is naturally radioactive. This can produce unjustified concern and subsequently perturb the market of these products. The radon exhalation rates for all ceramic tile companies were in the ranges 28-44 mBq.m -2 .h -1 and 2.0 to 4.8 mBq.kg -1 .h -1 . The porosity of ceramic tiles is in the range 0.19-0.28. The radium activity of ceramic tiles was found to be in the range 16-38 Bq.kg -1 for the glazed surface and 23-64 Bq.kg -1 for the clay surface, respectively. The average equivalent dose in contact with the ceramic surface was found to be 22 mSv.y -1 . The exposure at working level at the ceramic tile surface was in the range 2.4-3.8 WL. This gives a risk indication to people who spend a long time in closed ceramic tile stores, who should avoid staying for a long time in such places.

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