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Innovating physics teaching through teachers’ learning communities and action research
Get PDFThe paper provides information, foundation and supporting evidence about a possible structure of a research-based in-service program for physics teachers aimed at improving their use of the laboratory. We present our model and we
describe the CoLLabora project where the model was first implemented. The results suggest that the program actually produced positive changes in the participants’ ideas about the laboratory, its actual use in their teaching practice, and in students’ outcomes. We also present two case studies and we outline some research lines and the ‘teacher training cascade’ that have developed from the project
Remote handling of radioactive targets at the SPES facility
Get PDFSPES (Selective Production of Exotic Species) is a new facility being developed by Legnaro National Laboratories of INFN. Once operational, it will be able to generate high-intensity RIB (Radioactive Ion Beams) for research in the field of nuclear physics, and investigate medical applications through the ISOLPHARM project. The interaction of a 40 MeV 200 μA primary beam produced by a cyclotron
proton driver with a multi-foil uranium carbide target leads to the production of the radioactive isotopes of interest. Collisions take place within the Target Ion Source (TIS) unit, which is the core of the SPES project. During the operation, a periodic replacement of the TIS unit is required to maintain process efficiency. Automated systems can perform critical tasks under such highly radioactive conditions, including handling, transporting, and storing the TIS unit without human intervention. For this reason, a remote handling framework is currently being developed to meet the functional and safety requirements of the project. In this paper, the SPES target area is presented. Here, remote handling systems ensure the proper operation of
the facility, preventing staff from being exposed to high dose rates or contamination problems
New technologies for radioactive waste monitoring: Results and perspectives from recent experience
Get PDFWith the initial support of the INFN-Energy committee throughout the last ten years a few activities have been pursued aimed at the improvement of radioactive waste management. Nowadays new technologies make possible the
development of low-cost systems capable of monitoring the radioactivity coming out of (spent) nuclear fuel casks or radwaste drums. Simple, compact and effective radiation counters were developed at INFN for the detection of gamma rays and neutrons, suitable to be deployed as a distributed network for the real time monitoring of radioactive waste from the very low up to the highest level, and possibly
preluding to a mass deployment benefitting both safety and security. Indeed, in such a framework any change in counting rates, or even a sensor blackout, could be interpreted as a possible safety or security breach. Techniques for sorting and segregating the radioactive waste have also been studied and a dedicated prototype for the gamma/visible imaging with spectroscopic features is currently being developed. On top of the new interesting technical features accessible by means of distributed networks of devices, one should also focus on the psychological impact they could have on the general public acceptability of a finely monitored repository. Tests performed on radioactive waste of all categories, including spent fuel, showed quite promising results
A new approach for the treatment and conditioning of excess nuclear materials and implications for repository disposal
Get PDFOne of the most critical, and historically overlooked, considerations when employing nuclear materials is the treatment and conditioning strategy for their disposal. Selecting the correct strategy depends on a broad range of factors from the characteristics and size of the inventory, to the available resources and infrastructure. However, equally important as the product, is its compatibility with
both interim and final disposal requirements. While with smaller or less exotic inventories there are numerous options available, those options become more limited and challenging as inventories become larger, more hazardous, more unusual, or more proliferation-attractive. This paper will review several of the “established” methods for the treatment and conditioning of nuclear material inventories, noting their relative advantages and disadvantages, and highlight a new approach which may provide a safer, simpler, versatile and more cost-effective process for treating
materials to prepare for disposal including the proliferation-attractive inventories. Furthermore, the paper will highlight the importance of defining interim storage
and final disposal requirements and how this new treatment approach provides the flexibility to tailor the product to the requirements for interim storage and geologic disposal, which are still evolving in most countries. The paper will conclude by reviewing the implications of this approach for countries and entities considering options for the management of known and potential inventories of excess nuclear materials
Issues in the experimental determination of electron screening effects in nuclear reactions of astrophysical interest
Get PDFIn fixed-target experiments at collision energies of astrophysical interest (100 keV), the dynamics of nuclear reactions between charged particles is affected by electrons bound to the projectile and target. Some measurements
involving atomic-like targets suggest deviations sensibly greater than theoretically expected for a screening effect due only to atomic electrons. This work aims to study
more in depth the degree of compatibility of experimental data with standard atomic theory. Traditional methods to estimate screening effects from data are presented,
discussing their strengths and limitations, and a different approach is proposed. It is underlined how empirical investigations on screening cannot be disentangled from
the problem of modelling the low-energy bare cross-section. The study was applied to the 6Li + p → 3He + α reaction
Monte Carlo study of 3D image reconstruction for boron dose distribution in BNCT with CZT-based Compton camera
Get PDFBoron Neutron Capture Therapy is an innovative and highly selective treatment against cancer. Nowadays in vivo boron dosimetry is an important issue to carry out such therapy in clinical environments. In this work, we study the
performance of a Compton camera detector based on a 3D CZT crystal for online dosimetry in BNCT using Monte Carlo simulations and the maximum likelihood expectation maximization method for tomography reconstruction
Hacktivists from the Inside: Collective Identity, Target Selection and Tactical Use of Media during the Quebec Maple Spring Protests
Get PDFMuch of the research on Anonymous has studied the group from an ethnographic perspective or focused on social media posts to learn what is most important for the movement. There have been only few attempts to analyze how hacktivists are choosing suitable targets for cyberattacks with protest objectives. The present study attempts to provide insight into their shared values by looking at interactions among Anonymous members on public chatrooms during the four months of the Quebec student demonstrations known as the 2012 Printemps Érable protests. A thematic analysis was performed to categorize the important themes. The results show that the core values of Anonymous’s group is congruent to that of
Anonymous’s social media accounts, emphasizing freedom of expression, often linked to freedom of speech and freedom
of information as integral to the target selection process. Also, participants in the chatroom proposed traditionally suitable targets (i.e., the government, the police, political parties) and seems to agree upon which targets should be rejected such as traditional news media, deemed important to diffuse its message and provide information about its operations
Le renseignement criminel au service de la lutte contre la cybercriminalité : l’exemple français de la gendarmerie nationale
Get PDFCet article propose une analyse synthétique de la cybercriminalité au travers de l’état de la menace cyber réalisé par la gendarmerie nationale. L’ampleur de cette forme de délinquance est aujourd’hui telle que l’action des enquêteurs et des magistrats, au cas-par-cas, dans une logique procédurale d’individualisation, ne saurait, à elle seule, avoir raison d’un phénomène aussi massif. Récemment reformulé sous l’angle de l’intelligence-led policing (ILP), le renseignement criminel propose une nouvelle approche de la délinquance, proactive, orientée sur une compréhension préalable des situations afin de proposer des solutions adaptées, diversifiées et innovantes. L’écosystème cyber se prête particulièrement aux méthodes d’analyse et aux stratégies proposées par le renseignement criminel. La détection et la compréhension des menaces y sont autorisées par la cyber threat intelligence (CTI) et les solutions d’entrave pour les forces de sécurité intérieures ne se limitent plus à la répression pénale, mais font appel à des dispositifs toujours plus sophistiqués
Anti-stars in the Milky Way and primordial black holes
No full textAstronomical data of the several recent years which present an evidence in favour of abundant antimatter population in our Galaxy, Milky Way, are analysed. The data include: registration of gamma-rays with energy 0.511 MeV, which surely originate from electron-positron annihilation at rest, very large flux of anti-helium nuclei, discovered at AMS, and 14 stars which produce excessive gammarays with energies of several hundred MeV which may be interpreted as indication that these stars consist of antimatter. Theoretical predictions of these phenomena, made much earlier ago are described
Status and prospects of discovery of 0νββ decay with the CUORE detector
No full textIn this contribution we present the achievements of the CUORE experiment so far. It is the first tonne-scale bolometric detector and it is in stable data taking since 2018. We reached to collect about 1800 kg×yr of exposure of
which more than 1 ton×year have been analysed. The CUORE detector is meant to search for the neutrinoless double β decay (0νββ) of the 130Te isotope. This is a beyond Standard Model process which could establish the nature of the neutrino to be Dirac or a Majorana particle. It is an alternative mode of the two-neutrinos double β decay, a rare decay which have been precisely measured by CUORE in the 130Te. We found no evidence of the 0νββ and we set a Bayesian lower limit of 2.2 ×1025yr on its half-life. The expertise achieved by CUORE set a milestone for any future bolometric detector, including CUPID, which is the planned next generation experiment searching for 0νββ with scintillating bolometers