Search results for " Radioactive"
showing 10 items of 47 documents
Chronospeciation of uranium released in soil during a long-term DU shell weathering experiment.
2021
Corrosion process was investigated of depleted uranium (DU) ammunition fragments buried for three years in aerobic soils continuously irrigated with water. The continuing corrosion process was triggered through formation of soluble uranyl oxyhydrate phases such as metaschoepite and becquerelite, which were identified by micro-Raman and X-ray diffraction spectroscopy. The soil was not amended by phosphates and, therefore, no uranyl phosphates were found as corrosion products on the DU surfaces by X-ray photoelectron spectroscopy. A speciation modelling at high temporal sequence (chronospeciation approach) indicated that the abundant Fe oxyhydroxides in the soil immobilized the U(IV) released…
Induction of skeletal abnormalities and autophagy in Paracentrotus lividus sea urchin embryos exposed to gadolinium.
2017
Abstract Gadolinium (Gd) concentration is constantly increasing in the aquatic environment, becoming an emergent environmental pollutant. We investigated the effects of Gd on Paracentrotus lividus sea urchin embryos, focusing on skeletogenesis and autophagy. We observed a delay of biomineral deposition at 24 hours post fertilization (hpf), and a strong impairment of skeleton growth at 48 hpf, frequently displayed by an asymmetrical pattern. Skeleton growth was found partially resumed in recovery experiments. The mesodermal cells designated to biomineralization were found correctly migrated at 24 hpf, but not at 48 hpf. Western blot analysis showed an increase of the LC3-II autophagic marker…
Effective and environmental half-lives of radiocesium in game from Poland.
2021
For the first time changes in the 137Cs activity in game throughout Poland, including its most contaminated part known as the Opole Anomaly, were analyzed. Due to its long physical half-life, 137Cs continuously demonstrates high activity both in soil and biota. The species of game mammals, along with forest fruit and mushrooms, tend to accumulate this radionuclide, becoming one of the main sources of secondary contamination in people. In this study the 137Cs activity in roe deer, wild boar and red deer muscle tissue samples, within the years of 1986–2019, were studied. The effective and environmental half-lives were determined for each of the mentioned species for four regions including NE …
Population of lead isotopes in binary reactions using a Rb 94 radioactive beam
2020
8 pags., 9 figs.
A radiometric and petrographic approach to risk assessment at Alte Madonie Mounts region (Sicily, Italy)
2013
The main goal of this work was to assess the radiological hazard at Alte Madonie Mounts region (north-central Sicily, Italy) in response to rumours of an increase in the incidence of cancer in this area. A correlation between the natural radionuclide contents and the petrographic features of the soil and rock samples was also evaluated. A total of 41 samples of selected soils and rocks were collected, powdered, dried and sealed in 'Marinelli' beakers for 20 d prior to measurement to ensure that a radioactive equilibrium between (226)Ra and (214)Bi had been reached. A gamma-ray spectrometer was used to quantify the radioactivity concentrations. To determine (238)U and (232)Th activities, the…
Comparison of gamma-ray coincidence and low-background gamma-ray singles spectrometry
2011
Aerosol samples have been studied under different background conditions using gamma-ray coincidence and low-background gamma-ray singles spectrometric techniques with High-Purity Germanium detectors. Conventional low-background gamma-ray singles counting is a competitive technique when compared to the gamma-gamma coincidence approach in elevated background conditions. However, measurement of gamma-gamma coincidences can clearly make the identification of different nuclides more reliable and efficient than using singles spectrometry alone. The optimum solution would be a low-background counting station capable of both singles and gamma-gamma coincidence spectrometry.
RADIONUCLIDE CONCENTRATIONS IN AIR PARTICULATE AT PALERMO (ITALY) FOLLOWING FUKUSHIMA ACCIDENT
2012
Following the Fukushima accident, a series of samplings were carried out with a daily frequency to detect the arrival of radioactive contamination in air at Palermo (Italy) and to follow its evolution during the time. Air particulate collection was performed by suction of atmospheric air through cellulose filter paper by means of a high-volume air sampler (∼15 000 m(3) d(-1)). Spectrometric analysis of the filters highlights the presence of (131)I, (134)Cs, (137)Cs and, only for a few samples, traces of (132)Te-(132)I and (136)Cs. Maximum airborne concentrations were 883 μBq m(-3) for (131)I (only particulate), 81 μBq m(-3) for (137)Cs and 70 μBq m(-3) for (134)Cs. From a dose to population…
A chamber to test the response of radon detectors to changing environmental conditions.
2011
Radon risk assessment is carried out with accurate measurements with active or passive instrumentation. All radon detectors must be calibrated and tested using a radon chamber containing a known concentration of radon produced by specific sources of 226Ra. Some of the chambers can also be used to test the response of detectors as a function of environmental conditions. In this case, it can be inferred a calibration curve with respect to changing of the parameter considered. For this aim, a new chamber radon was designed and realized to perform both calibration of instruments and to study the detector response in a large range of variation of the environmental parameters (pressure, 700 - 110…
A radiometric and petrographic interpretation of discrepancies on uranium content in samples collected at Alte Madonie Mounts region (Sicily, Italy)
2013
Abstract The main goal of this work is to evaluate a correlation between anomalous Uranium (U) content and petrographic features of some soil and rock samples collected at Alte Madonie Mounts region (North-central Sicily, Italy). A total of 41 samples of selected soils and rocks were collected, powdered, dried and sealed in “Marinelli” beakers for 20 days before the measurement to ensure that radioactive equilibrium between 226 Ra and 214 Bi was reached. Gamma-ray spectrometric analysis was used to quantify radioactivity concentrations. Mineralogical and chemical features of the samples were determined by X-ray Fluorescence (XRF), X-ray Diffractometry (XRD), Attenuated Total Reflection-Four…
In-soil radon anomalies as precursors of earthquakes: A case study in the SE slope of Mt. Etna in a period of quite stable weather conditions
2012
In-soil radon concentrations as well as climatic parameters (temperature, atmospheric pressure and relative humidity) were collected in St. Venerina (Eastern Sicily - Italy) from March 19th to May 22nd 2009, close to an active fault system called Timpe Fault System (TFS), which is strictly linked to the geodynamics of Mt. Etna. During the monitoring period no drastic climatic variations were observed and, on the other hand, important seismic events were recorded close to the monitoring site. A seismic swarm composed of 5 earthquakes was observed in the Milo area on March 25th (M-max = 2.7) at just 5.1 km from the site, and on May 13th an earthquake of 3.6 magnitude was recorded in the terri…