In the framework of R&D studies for the improvement of radioactive source efficiencies prepared on thin films for 4pibeta-gamma coincidence counting, a comparative study on two drying methods has been undertaken in our laboratory (BNM-Laboratoire National Henri Becquerel, France). The standard method of evaporation at atmospheric pressure and a method based on freeze-drying using commercial equipment are compared. The preliminary results of this study obtained with 65Zn sources are presented and a significant improvement of the detection efficiencies to the electron emission for freeze-dried sources is shown. In the course of validation of this method, other radionuclides were studied and, up to now, the results confirm the better crystallization homogeneity achieved for freeze-dried sources.
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http://dx.doi.org/10.1016/j.apradiso.2004.04.006 | DOI Listing |
Sci Rep
January 2025
Institut de Recherche en Astrophysique et Planétologie, UPS/CNRS/CNES, F-31400, Toulouse, France.
The radioactive gas radon-222, a fluid and aerosol tracer in Earth's lithosphere and atmosphere, can also reveal subtle rock physics processes in extraterrestrial environments, such as those involving water, but remains poorly constrained in planetary bodies due to the limited number of samples available. Here we measure the effective radium-226 concentration (EC) of six Martian and nine lunar meteorites to derive radon source terms for Martian and lunar rocks. EC values are 0.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
Radiological Physics and Advisory Division, Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Anushaktinagar, Mumbai 400094, India.
Experiments were conducted in controlled laboratory conditions to determine the size-resolved CCN (Cloud Condensation Nuclei) activity of sub micrometer-sized aerosols containing nuclear fission products (CsI and CsOH) and abundant ambient inorganic aerosols ammonium sulphates ((NH)SO), ammonium chloride (NHCl), sodium nitrate (NaNO), and sodium chloride (NaCl). The presence of these atmospheric-relevant compounds internally mixed with fission product compounds has the potential to affect the capacity of ambient particulates of aerosols to absorb water and function as CCN. Once in the atmosphere, the dynamics of airborne radionuclides and subsequently their fate gets affected by dry and wet deposition processes.
View Article and Find Full Text PDFJ Environ Manage
January 2025
Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou, 510006, China. Electronic address:
Thallium (Tl), recognized for its high toxicity, is subject to stringent international regulations regarding its permissible concentrations at ultra-trace levels. In this study, titanium dioxide (TiO) was integrated with potassium (K)-rich biochar to create TiO/biochar (TiO/BC) composites for synergistic enhancement in ultra-trace Tl(I) removal, focusing on achieving concentration below the rigorous local threshold of 0.1 μg/L for drinking water.
View Article and Find Full Text PDFBiomed Phys Eng Express
January 2025
Physics and Applied Mathematics, Pakistan Institute of Engineering and Applied Sciences, Qau, Islamabad, Islamabad, 44000, PAKISTAN.
The current study investigated the geometry, design and solid angle impacts on full energy peak efficiency (FEPE) of NaI(Tl) detectors for a line source. A line source is fabricated using 99mTc solution filled in a borosilicate glass tube of inner diameter 3 mm, tube wall thickness 2.5 mm and length 12.
View Article and Find Full Text PDFMar Pollut Bull
January 2025
School of Life Sciences, University of Essex, Colchester CO4 3SQ, UK.
Although oil and gas (O&G) derived produced waters and drill cuttings are known to contain enhanced levels of naturally occurring radium-228 (Ra) and radium-226 (Ra), most relevant ecological impact assessments have excluded radiological hazards and focus on other important contaminants, such as hydrocarbons and metals. Also, due to restricted access to the delimiting safety zone around operational O&G platforms, the few previous radioecological risk assessment studies have been conducted using seawater samples collected far from the main discharge point and applying default dilution and transfer factors to estimate concentrations of contaminants in biota. In this case study, sediment cores were collected close to a former O&G platform, Northwest Hutton (NWH), that used to be in the UK North Sea (61.
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