47 research outputs found
Thinking about platforming with more traditional mediatization: Lessons from audiovisual analysis
Since the mid-1990s, film and television industries are more and more confronted with the appearance of new intermediation services which have created platforms. In a project funded by the Social Sciences and Humanities Research Council of Canada (SSHRC), we try to analyze the place and role that these new services are taking in the audiovisual sector. Our corpus is composed of the platforms of four companies that have developed activities on a vast international scale, Netflix (with its service of the same name), Amazon (Prime Video service), Disney (Disney+) and Apple (Apple TV+). Based on our corpus, it seems to us that some changes have been the result of firms’ activities, but that it is not as linear as it may appear at first sight. Transformations are at work but there is also some “Old Media Persistence.” Thus, we find a certain “contamination” of old practices originating from the organization of industrial channels and forms in the mutations currently presented by these new intermediation services
Monte Carlo methodologies for neutron streaming in diffusion calculations - Application to directional diffusion coefficients and leakage models in XS generation
Neutron transport calculations by Monte Carlo methods are finding increased application in nuclear reactor simulations. In particular, a versatile approach entails the use of a 2-step procedure, with Monte Carlo as a few-group cross section data generator at lattice level, followed by deterministic multi-group diffusion calculations at core level.
In this thesis, the Serpent 2 Monte Carlo reactor physics burnup calculation code is used in order to test a set of diffusion coefficient models, as well as neutron leakage methodologies at assembly level. The tests include novel anisotropic diffusion coefficient and heterogeneous leakage models developed and implemented by the author.
The analyses are mainly focused on a sodium-cooled fast reactor system, for which few-group cross section data was generated by stochastic methods with Serpent 2. The quality of the full-core diffusion results is evaluated by contrasting system eigenvalues and power distributions against detailed, full-core reference solutions also supplied by the Serpent 2 code and the same nuclear data library.
Whereas the new anisotropic diffusion coefficient formalism exhibits improved performance in the fast reactor system studied, there are restrictions to its applicability in other reactor designs. The newly proposed leakage model has a similar performance to that one of albedo ite-rations, and provides valuable information about the space-energy coupling of the scalar neutron flux at lattice level. This hitherto unavailable information does not entail a significant computational cost.
In sodium-cooled fast reactor calculations, the quality of diffusion theory results can be improved by either using directional diffusion coefficients and a fine energy mesh, or via leakage-corrected discontinuity factors. These factors can be calculated using net neutron currents supplied by heterogeneous leakage models. Preliminary results from this research also suggest that the studies maybe extended to graphite-moderated, gas-cooled reactors
Intercomparison exercise on difficult to measure radionuclides in spent ion exchange resin
A need for method validation in radiochemical analyses of decommissioning waste is a challenging task due to lack of commercial reference materials. Participation in an intercomparison exercise is one way for a laboratory to assess their performance and validate their analysis results. A three-year project within the Nordic Nuclear Safety Research (NKS) community was initiated in order to carry out intercomparison exercises on difficult to measure (DTM) radionuclides in real decommissioning waste. Both Nordic and Non-Nordic laboratories participated. This paper reports the results from the final year of the project focusing on beta- and gamma emitter (i.e., easy to measure, ETM) analysis in spent ion exchange resin. The assigned values were derived from the participants' results according to ISO 13528 standard and the performances were assessed using z scores. The results showed generally good performances for both DTMs and ETMs.Peer reviewe
Gravity-darkening Analysis of the Misaligned Hot Jupiter MASCARA-4 b
MASCARA-4 b is a hot Jupiter in a highly misaligned orbit around a rapidly rotating A3V star that was observed for 54 days by the Transiting Exoplanet Survey Satellite (TESS). We perform two analyses of MASCARA-4 b using a stellar gravity-darkened model. First, we measure MASCARA-4 b's misaligned orbital configuration by modeling its TESS photometric light curve. We take advantage of the asymmetry in MASCARA-4 b's transit due to its host star's gravity-darkened surface to measure MASCARA-4 b's true spin–orbit angle to be 104°+7°-13°. We also detect a ~4σ secondary eclipse at 0.491 ± 0.007 orbital phase, proving that the orbit is slightly eccentric. Second, we model MASCARA-4 b's insolation including gravity darkening and find that the planet's received X-ray and ultraviolet flux varies by 4% throughout its orbit. MASCARA-4 b's short-period, polar orbit suggests that the planet likely underwent dramatic orbital evolution to end up in its present-day configuration and that it receives a varying stellar irradiance that perpetually forces the planet out of thermal equilibrium. These findings make MASCARA-4 b an excellent target for follow-up characterization to better understand the orbital evolution and present-day environment of planets around high-mass stars
Discovery of δ Scuti Pulsations in the Young Hybrid Debris Disk Star HD 156623
The bRing robotic observatory network was built to search for circumplanetary material within the transiting Hill
sphere of the exoplanet β Pic b across its bright host star β Pic. During the bRing survey of β Pic, it simultaneously
monitored the brightnesses of thousands of bright stars in the southern sky (V ; 4–8, δ −30°). In this work, we
announce the discovery of δ Scuti pulsations in the A-type star HD 156623 using bRing data. HD 156623 is
notable as it is a well-studied young star with a dusty and gas-rich debris disk, previously detected using ALMA.
We present the observational results on the pulsation periods and amplitudes for HD 156623, discuss its
evolutionary status, and provide further constraints on its nature and age. We find strong evidence of frequency
regularity and grouping. We do not find evidence of frequency, amplitude, or phase modulation for any of the
frequencies over the course of the observations. We show that HD 156623 is consistent with other hot and highfrequency pre-main sequence and early zero-age main sequence (ZAMS) δ Scutis as predicted by theoretical
models and corresponding evolutionary tracks, although we observe that HD 156623 lies hotter than the theoretical
blue edge of the classical instability strip. This, coupled with our characterization and Sco–Cen membership
analyses, suggests that the star is most likely an outlying ZAMS member of the ∼16 Myr Upper Centaurus-Lupus
subgroup of the Sco–Cen associatio
DTM-Decom III : Intercomparison exercise in analysis of DTM beta and gamma emitters in spent ion exchange resin
Personalized Risk Assessment for Prevention and Early Detection of Breast Cancer: Integration and Implementation (PERSPECTIVE I&I).
Early detection of breast cancer through screening reduces breast cancer mortality. The benefits of screening must also be considered within the context of potential harms (e.g., false positives, overdiagnosis). Furthermore, while breast cancer risk is highly variable within the population, most screening programs use age to determine eligibility. A risk-based approach is expected to improve the benefit-harm ratio of breast cancer screening programs. The PERSPECTIVE I&I (Personalized Risk Assessment for Prevention and Early Detection of Breast Cancer: Integration and Implementation) project seeks to improve personalized risk assessment to allow for a cost-effective, population-based approach to risk-based screening and determine best practices for implementation in Canada. This commentary describes the four inter-related activities that comprise the PERSPECTIVE I&I project. 1: Identification and validation of novel moderate to high-risk susceptibility genes. 2: Improvement, validation, and adaptation of a risk prediction web-tool for the Canadian context. 3: Development and piloting of a socio-ethical framework to support implementation of risk-based breast cancer screening. 4: Economic analysis to optimize the implementation of risk-based screening. Risk-based screening and prevention is expected to benefit all women, empowering them to work with their healthcare provider to make informed decisions about screening and prevention
Estudio sobre la factibilidad técnica de realizar fechado por trazas de fisión en las posiciones de irradiación del reactor RA-6
El método de datación geológica por trazas de fisióon se basa en la detección del daño que imprimen los fragmentos de fisión del Uranio contenido en las muestras geológicas durante el transcurso del tiempo. Para determinar la edad de una muestra, se deben conocer simultáneamente la cantidad de fisiones espontáneas ocurridas y la concentración de Uranio en el material. Esto obliga a irradiar las muestras en un reactor con flujo térmico, de manera de inducer fisiones solamente en el isótopo 235 y poder determinar la concentración de Uranio. El problema que presentan las posiciones de irradiación del reactor RA-6 es que el flujo no es completamente térmico allí, por lo cual las fisiones debidas a neutrones epitérmicos y rápidos no serán despreciables. De la misma manera, se detectarán trazas debidas a fisiones inducidas en átomos de ^2^3^8U y ^2^3^2Th. Para conocer las correcciones aplicables a las mediciones en las posiciones de este reactor, es necesario caracterizar el espectro de energía del flujo de neutrones rápidos. A tal fin, se utilizaron detectores de activación. Para realizar las mediciones, se debió calibrar el equipo de espectrometría gamma del laboratorio. Luego, se irradiaron diversos detectores de flujo y se analizaron los resultados. Finalmente, se determinó que es factible realizar fechado geológico por el método de trazas de fisión en la posición I6, estimándose las limitaciones que ofrecen los valores de flujo obtenidos a la aplicación de este métod