A Comparison of Retrospective Radon Gas Measurement Techniques Carried Out in the Serbian Spa of Niska Banja

Indoor radon retrospective concentrations were obtained and compared using two radon measurement methods. Both methods rely on the measurement of the long-lived radon progeny (210)Pb, collected either on the surfaces (surface trap technique), most frequently glass, or in a volume trap, usually sponge from furniture (volume trap technique). These techniques have been used to retrospectively estimate radon gas concentrations that have existed in dwellings in the past. The work presented here compares the results provided by the surface trap technique devised at the University College of Dublin, Ireland, and the volume trap technique devised at the Scientific Research Center, Mol, Belgium. The field campaign was carried out by the research team of the ECE Laboratory of the Vinca Institute of Nuclear Sciences at the spa of Niska Banja, identified as a region of Serbia with a high indoor radon and ground water radium and radon content

Soil gas mapping in the vicinity of Nikola Tesla thermo power plant disposal field

This paper presents the results of identification of natural ionizing irradiation in the vicinity of Nikola Tesla B power plant ash disposal field. The investigations have comprised the determination of natural gas (radon and thoron) activities with a passive discriminative nuclear track detector (CR 39) in the air column of the depth of 80 cm in the soil. The determination of gamma dose rate has been given as well, including the corresponding GPS coordinates of 28 measuring points

Synthesis and antibacterial activity of iron manganite (FeMnO 3 ) particles against the environmental bacterium Bacillus subtilis †

Nanocrystalline iron manganite powder was synthesized using the sol-gel combustion process, with glycine as fuel. It was further calcined at 900 C for 8 h, resulting in the formation of a loose cubic FeMnO 3 powder with a small specific surface area, net-like structure and plate-like particles as confirmed by XRD, N 2 physisorption, FESEM and TEM analyses. The metal ion release was studied by ICP-OES and showed that less than 10 ppb of Fe or Mn ions were released by leaching in water, but 0.36 ppm Fe and 3.69 ppm Mn was found in LB (Luria-Bertani) bacterial medium. The generation of reactive oxygen species (ROS) was monitored in distilled water and bacterial medium and showed that FeMnO 3 particles do not generate O 2 c À ions with or without UV irradiation, but synthesize H 2 O 2 and show an antioxidative effect. Besides the higher stability of FeMnO 3 particles in aqueous solution they showed an inhibitory effect on Bacillus subtilis growth in LB medium even at low concentrations (0.01 mg ml À1), but not in BHI medium even at 1 mg ml À1. This study points out that the mechanism of antibacterial action of engineered metal oxides needs continued investigation and specific experimental controls