Search results for "nuclide"

Inter/intramolecular Cherenkov radiation energy transfer (CRET) from a fluorophore with a built-in radionuclide.

2014

The Cherenkov radiation (CR) from [(18)F]-FDG, [(177)Lu]-LuCl3 and [(90)Y]-YCl3 was detected and CR energy transfer (CRET) to several fluorophores was examined. Subsequent fluorescence emission was found to be a function of the position of absorption bands with respect to the CR peak, energy of emitted particles, radionuclide/fluorophore loading, and fluorophore brightness. A variant of the best fluorophore with a built-in radionuclide was synthesized to achieve inter- and intra-molecular CRET.

A Bayesian approach to assess data from radionuclide activity analyses in environmental samples

2007

A Bayesian statistical approach is introduced to assess experimental data from the analyses of radionuclide activity concentration in environmental samples (low activities). A theoretical model has been developed that allows the use of known prior information about the value of the measurand (activity), together with the experimental value determined through the measurement. The model has been applied to data of the Inter-laboratory Proficiency Test organised periodically among Spanish environmental radioactivity laboratories that are producing the radiochemical results for the Spanish radioactive monitoring network. A global improvement of laboratories performance is produced when this pri…

MAIN CONCLUSIONS OF THE EC-HUMICS PROJECT: “EFFECTS OF HUMIC SUBSTANCES ON THE MIGRATION OF RADIONUCLIDES: COMPLEXATION AND TRANSPORT OF ACTINIDES”

2000

Accumulation and discharge behavior of Cs-137 by zebra fish (Brachydanio rerio) in different aquatic environments

1990

The uptake and release kinetics of137Cs from water by the tropical fishBrachydanio rerio has been studied under controlled laboratory condition. The accumulation of this radionuclide from food was avoided by feeding the fishes separately in an inactive environment. A steep inverse dependence of bioconcentration factor (BCF) with potassium concentration has been observed. This can formally be described by the equation BCF=5.2 · [K+]−0.44. The elimination rate constant K in fresh water conditions has been found to have a magnitude of 0.014±0.03 d−1 which corresponds to a biological half-life of 51±10 days. The uptake and release kinetics ofBrachydanio rerio has been compared with earlier stud…

Nanoparticles and their influence on radionuclide mobility in deep geological formations

2012

International audience; This article gives an overview of the current status of knowledge concerning the role of nanoparticles (inorganic and organic) in deep geological host rocks and the potential influence of these nanoparticles on radionuclide migration in far-field systems. The manuscript is not intended to be a full review paper or overview paper concerning nanoparticles, here the intention is to refer to recent publications but to highlight the progress made in the 6th framework project IP FUNMIG (Fundamental processes of radionuclide migration) and the open literature over the past 5 a concerning the process understanding of nanoparticle related issues in the three host rock formati…

MicroSISAK: continuous liquid–liquid extractions of radionuclides at 0.2 mL/min

2013

Abstract Continuous liquid–liquid extraction of short-lived radionuclides has traditionally been performed with the SISAK system consisting of static mixers and H-centrifuges for phase separation. SISAK operates at flow rates of typically 1 mL/s. Thus, it produces large volumes of radioactive liquid waste that is difficult to dispose of. Therefore, it has been aimed to develop and use a further miniaturised extraction unit based on microtechnology and precision engineering to reduce the flow rate by at least two orders of magnitude. The accordingly developed MicroSISAK device is a micro membrane extractor in which a micromixer element with 2 × 16 feed channels of 30 µm width followed by a 6…

The Origin of Heavy Metals and Radionuclides Accumulated in the Soil and Biota Samples Collected in Svalbard, Near Longyearbyen

2017

Abstract Heavy metals and radioactive compounds are potentially hazardous substances for plants, animals and humans in the Arctic. A good knowledge of the spatial variation of these substances in soil and primary producers, and their sources, is therefore essential. In the samples of lichen Thamnolia vermicularis, Salix polaris and Cassiope tetragona, and the soil samples collected in 2014 in Svalbard near Longyearbyen, the concentrations of the following heavy metals were determined: Mn, Ni, Cu, Zn, Cd, Pb and Hg, as well as the activity concentrations of the following: K-40, Cs-137, Pb-210, Pb-212, Bi-212, Bi-214, Pb-214, Ac-228, Th-231 and U-235 in the soil samples. The differences in th…

The Use of Moss Pleurozium schreberi (Brid.) Mitt. as Bioindicator of Radionuclide Contamination in Industrial Areas of Upper Silesia

2017

Abstract Mosses are good bioaccumulators of radionuclides and from the 60 of the last century, they are used as bioindicators of radioactive contamination in the environment. Concentration of impurities in moss represent the accumulation in mosses during the past 2-3 years. As a result, the moss composition analysis provides information on an average contamination within a few vegetation seasons. During our survey the measurements of radionuclide activity concentrations in P. schreberi transplanted from places relatively clean to heavily contaminated areas of Upper Silesia were carried out. An increase in the radionuclides activity concentrations in P. schreberi transplants may indicate not…

Assessment of Gamma Dose Rate at Mine Waste Dump

2013

Abstract Exploitation of coal deposits in Upper Silesia is associated with production of large quantities of waste deposited at dumps. The tested samples from five dumps showed different radioactivity from each other. Radioactivity measurements made it possible to analyze the degree of risk with the factors specified by UNSCEAR such as radium equivalent activity Raeq, internal Ein and external Eex occupancy factor. There is a raised level of radiation in dumps as compared with outside dump areas. In the study area, however, there is no risk associated with elevated levels of radiation in relation to standards established by the Council of Ministers of the ionizing radiation dose limits.

Annual effective dose and excess life time cancer risk assessment from tobacco plants

2019

Cigarette smoking is one of the pathways that might cause radiation exposure due to the presence of radioactive elements in tobacco leaves used in the manufacture of cigarettes. From the health point of view, the knowledge of radioactivity content of the various radionuclides in tobacco leaves and their derivative products is important to assess the radiological effects associated with tobacco smoking for smokers. In this work, naturally occurring radionuclides 226Ra, 232Th and 40K and man-made 137Cs were measured in tobacco using gamma-ray spectrometry. Results show that the average concentrations of 226Ra, 232Th and 40K vary from 4.30 ± 0.2 to 11.85 ± 0.7 (average 8.17), 1.35 ± 0.1 to 16.…