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GeoDescriber x GeoLLM : Faire parler la donnée énergétique
No full textInternational audienceThe GeoDescriber x GeoLLM project makes local energy data more understandable for communities. GeoDescriber automatically generates descriptive texts from territorial data, which GeoLLM then reformulates to enhance fluency and readability. This hybrid approach combines analytical rigor with editorial quality, making technical data intelligible for local stakeholders and showcasing the potential of language models to support the energy transition
Nonlinear statistics evolution of extreme wave fields over strongly reflective plane beaches
No full textInternational audienceThe description of complex wave processes, in addition to the shoaling problem, is often cumbersome even for the evolution of regular waves. For reflection under the regime of wave breaking, the surf similarity is generally accepted as the leading parameter controlling the reflection rates and types of breakers. While little is known about the effect of reflection rates on the formation of extreme nonlinear waves, some debate has arisen regarding whether high reflection rates enhance the nonlinearity at the tail of the wave height distribution through its Gram-Charlier approximation proxies (excess kurtosis and skewness). In this work, we provide theoretical evidence that at very steep beaches of smooth composition, the reflection rate nearing unity will tend to stabilize the excess kurtosis otherwise generated by shoaling and controlled in magnitude by the bottom slope magnitude. We further verified this result through fully nonlinear numerical simulations, reaching a good agreement
Assessment of the tritium analysis performance of a nonylphenol-ethoxylate-free liquid scintillator by interlaboratory comparison
No full textInternational audienceWith a view to using liquid scintillators compliant with the REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) regulations, some laboratories have expressed an interest in testing the ProSafe LT+ , a liquid scintillator without nonylphenol-ethoxylates (NPE). In order to evaluate the impact of using this new liquid on the analysis results, the CETAMA consortium organised two interlaboratory comparisons. Two ranges of tritium activity were selected to meet the needs of environmental and waste monitoring. 23 laboratories took part in these exercises, comparing results obtained with Prosafe LT+ to those obtained with NPE-containing liquid scinitllators. From the results it was seen that the background and the background noise obtained with the nonylphenol-ethoxylates-free liquid scintillator are not significantly different from that of the usual liquid scintillator, whether for the waste or environmental domain, over short (15 min) or long (200 min) counting times. Furthermore, the decision threshold and the detection limit values estimated with ProSafe LT+ were no different from those of usual scintillators. However, for the measurement of samples, and particularly for samples with a tritium activity above 15 Bq/kg, the ProSafe LT+ presented a reduced measurement quality compared to the nonylphenol-ethoxylates-containing LS i.e. the measurement uncertainty obtained with ProSafe LT+ is systematically higher. In light of the results obtained through this study, the authors recommend the use of the ProSafe LT+ with the proviso that the deterioration in measurement uncertainty be taken into account and found to be compatible with a laboratory’s individual needs
Formal series for linear representations of timed colored Petri nets
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SPH modelling of water flow inside a fixed and undeformable porous medium using a Riemann based formulation
No full textInternational audienceA weakly-compressible Smoothed Particle Hydrodynamics (SPH) model for the simulation of water seepage in a fixed and undeformable porous matrix is proposed in this paper. Within this model, the macroscopic governing equations of mass and momentum are expressed using an averaging process on an elementary volume of porous medium. A first set of particles is used for modelling the fluid, while a second one is employed for the porous structure to compute the volume fraction involved in the volume-averaged equations. The stabilization of the fluid model, based on a Riemann solver, is free of any diffusion parameter and results in regular and accurate pressure fields. Moreover, a Boundary Integral Method is chosen in this work to handle wall boundary conditions, with use of the so-called Español and Revenga laplacian operator. To the authors’ knowledge, both this stabilization and wall treatment technique have never been applied yet to this field of application. The validation of the present model on three test-cases demonstrates its strong reliability, showing good agreement with numerical and experimental results from the literature
Indoor turbulent airflow modelling with a new integral buoyant wall function
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Modélisation et analyse économique du comportement des acteurs sur les marchés énergétiques: Des producteurs aux consommateurs
No full textTowards a formation model of the Neanderthal symbolic accumulation of herbivore crania: Spatial patterns shaped by rockfall dynamics in Level 3 of Des-Cubierta Cave (Lozoya valley, Madrid, Spain)
No full textInternational audienceUnderstanding formation processes is crucial for interpreting sites with complex sedimentary histories and exceptional archaeological records, such as Level 3 of Des-Cubierta Cave. This Middle Paleolithic unit contains an assemblage of anthropically modified ungulate horned crania, Mousterian lithics, and evidence of fire use, all preserved in a clast-supported gravel deposit shaped by successive rockfalls. This study integrates geostatistical analyses with traditional spatial and taphonomic methods to examine the cone-shaped sedimentary structure that dominates the level and its influence on the spatial distribution and preservation of archaeological materials. The results reveal distinct spatial patterns for geological and archaeological materials, indicating separate formation dynamics. Size-based spatial analyses of boulders characterize the morphology of the conical structure, highlighting size sorting and intensity variations that may indicate sedimentary hiatuses. Bone refitting analysis suggests limited post-depositional movement, with material distribution shaped by the conical sedimentary structure and karst gallery morphology. Variability in crania preservation correlates with proximity to the cone’s apex and elevation, with better-preserved specimens in central areas and more fragmented remains in zones affected by erosive and edaphic processes. These findings underscore the value of integrating geostatistical and traditional archaeological approaches to advance interpretations of spatial and temporal patterns in karst environments and provide a methodological approach for examining sites with similar sedimentary histories. Moreover, the results support the interpretation of a recurrent, culturally motivated Neanderthal behaviour centred on the deliberate accumulation of large ungulate crania, pointing to a symbolic dimension in these practices
Design of an eco-industrial park for hydrogen and Fischer–Tropsch fuel deployment under the European policy framework
No full textInternational audienceOptimizing the hydrogen economy within industrial hubs represents a key aspect contributing to global decarbonization, yet current design approaches often overlook macroeconomic constraints, synergy opportunities and actor cooperation dynamics. This study addresses these gaps by proposing a multi-period, multi-resource integration framework for evaluating the feasibility of Fischer–Tropsch fuel production within an Eco-Industrial Park (EIP). A Mixed Integer Linear Programming (MILP) model is developed to minimize the annualized net present value of the system, considering both cooperative and non-cooperative governance schemes. The model integrates macroeconomic parameters such as EU ETS market prices, carbon dioxide sequestration costs, and RFNBO regulations, factors rarely accounted for in hydrogen-related EIP design. Results show that electricity is the dominant feedstock cost driver, contributing five times more than carbon dioxide to synthetic fuel production costs. Under favorable conditions, synthetic fuels must be priced at least three times higher than conventional fuels to justify investment, while under unfavorable conditions, this threshold rises to nine times. Cooperative governance enables economic gains through synthetic fuel sales, heat valorization and hydrogen production scaling, whereas non-cooperative governance leads to higher synthetic fuel prices due to resource bidding dynamics. These bidding dynamics, especially regarding carbon dioxide, are deeply influenced by policies, hence, the study concludes that policy design, as well as actor coordination, are critical to the viability of hydrogen-based EIPs in Europe