969 research outputs found
Quantification of uranium-238 in environmental samples using gamma-ray spectrometry
A large number of environmental samples are routinely measured world-wide using gamma-ray spectrometry some of its assets being easy sample preparation and comprehensive data for many radionu-clides in one analysis. Although other techniques can be considered more suitable for analysing 238U in environmental samples, it is also routinely done by gamma-ray spectrometry. One mainly uses γ-ray emissions following the decay of the first daughter, 234Th, for determining the 238U activity. However, the low-energy gamma-rays at 63 keV and 92.5 keV are very difficult to quantify in a robust way due to high attenuation and interferences. This paper quantifies parameters affecting the possibility of making robust quantification of 238U via 234Th using gamma-ray spectrometry. It addresses the use of correct decay data, suitable detectors, optimised sample size, enhanced spectral amplification, correction for peak interferences and control of background.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard
Status of Underground Radioactivity Measurements in HADES
The IRMM (Institute for Reference materials and Measurements) performs ultra low-level gamma-ray spectrometry at a depth of 225 m in the underground laboratory HADES. The facility currently houses 7 HPGe-detectors that are built and shielded using specially selected radiopure materials. The sandclay overburden of about 500 m water equivalent assures a muon flux reduction factor of about 5000, with
subsequent reduction of the background of the detectors, which makes it possible to obtain detection limits close to 100 µBq for certain radionuclides. This paper describes the aim of the IRMM activities in the HADES laboratory, the equipment and the measurement program and gives examples of radiopurity measurements carried out in order to develop better low-level measurements.JRC.DG.D.5-Nuclear physic
The core of secondary level quantum education: a multi-stakeholder perspective
Quantum physics (QP) education at the secondary school level is still in its infancy. Not only is there ongoing discussion about how to teach this subject, but there is also a lack of coherence in the selection of concepts to be taught, both across countries and over time. To contribute to this discussion, we investigated the perspectives of high school teachers, university-level physics educators, and physics education researchers regarding the essential concepts in QP and the corresponding illustrations that should be introduced at the secondary school level. We examined the prominence of different key concepts and illustrations, as well as the level of consensus among the various professional groups. Our analysis revealed that certain key concepts are universally valued across all professional groups, while others are specific to particular groups. Additionally, we explored the relationships between these key concepts and their corresponding illustrations. Overall, our study offers valuable insights into the perspectives of different stakeholders, emphasizing the essential concepts and visualizations that should be considered when designing and implementing the teaching of QP at the secondary school level
Role of TGF-β1 haplotypes in the occurrence of myocardial infarction in young Italian patients
<p>Abstract</p> <p>Background</p> <p>Transforming growth factor beta 1 (TGF-β1) gene play an important role in the acute myocardial infarction (AMI), however no investigation has been conducted so far in young AMI patients.</p> <p>In this study, we evaluated the influence of TGF-β1 polymorphisms/haplotypes on the onset and progression of AMI in young Italian population.</p> <p>Methods</p> <p>201 cases and 201 controls were genotyped for three TGF-β1 polymorphisms (G-800A, C-509T and Leu10Pro). The main follow-up end-points (mean follow-up, 107 ± 49 months) were death, myocardial infarction or revascularization procedures.</p> <p>Results</p> <p>Significant risk factors were smoking (p < 10<sup>-4</sup>), family history for coronary artery disease (p < 10<sup>-4</sup>), hypercholesterolemia (p = 0.001) and hypertension (p = 0.002). The C-509T and Leu10Pro polymorphisms showed significant differences (p = 0.026 and p = 0.004) between cases and controls.</p> <p>The most common haplotypes revealed a possible protective effect (GCT, OR 0.75, 95% CI 0.57–0.99, p = 0.042) and an increased risk of AMI (GTC, OR 1.51, 95% CI 1.13–2.02, p = 0.005), respectively.</p> <p>No statistical differences were observed in genotype distribution in the follow-up study between the two groups: 61 patients with subsequent events (13 deaths) and 108 without events.</p> <p>Conclusion</p> <p>Even though our results need to be further confirmed in larger studies, this is the first study reporting on a possible role of TGFβ1 common haplotypes in the onset of AMI in young patients.</p
The core of secondary level quantum education: a multi-stakeholder perspective
Quantum physics (QP) education at the secondary school level is still in its infancy. Not only is there ongoing discussion about how to teach this subject, but there is also a lack of coherence in the selection of concepts to be taught, both across countries and over time. To contribute to this discussion, we investigated the perspectives of N = 39 high school teachers, university-level physics educators, and physics education researchers regarding the essential concepts in QP and the corresponding illustrations that should be introduced at the secondary school level. We examined the prominence of different key concepts and illustrations, as well as the level of consensus among the various professional groups. Our analysis revealed that certain key concepts are universally valued across all professional groups, while others are specific to particular groups. Additionally, we explored the relationships between these key concepts and their corresponding illustrations. Overall, our study offers valuable insights into the perspectives of different stakeholders, emphasizing the essential concepts and visualizations that should be considered whe
Status of the GERDA experiment
The study of neutrinoless double beta (0nbb) decay is the only one presently known approach to the fundamental question if the neutrino is a Majorana particle, i.e. its own anti-particle. The observation of 0nbb decay would prove that lepton number is not conserved, establish that neutrino has a Majorana component and, assuming that light neutrino is the dominating process, provide a method for the determination of its effective mass. GERDA is a new 0nbb decay experiment which is currently taking data at the Laboratori Nazionali del Gran Sasso (LNGS) of INFN in Italy. It implements a new shielding concept by operating bare diodes made from Ge with enriched 76Ge in high purity liquid argon supplemented by a water shield. The aim of GERDA is to verify or refute the recent claim of discovery, and, in a second phase, to achieve a two orders of magnitude lower background index than past experiments, to increase the sensitive mass and to collect an exposure of 100 kg yr. The paper will discuss design, physics reach, and status of data taking of GERDA.JRC.D.4-Standards for Nuclear Safety, Security and Safeguard
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