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Current hygrothermal behaviour prediction models neglect the hysteresis phenomenon. This leads to a discrepancy between numerical and experimental results, and a miscalculation of buildings’ durability. In this paper, a new mathematical model of hysteresis is proposed and implemented in a hygrothermal model to reduce this discrepancy. The model is based on a symmetry property between sorption curves and uses also a homotopic transformation relative to a parameter [Formula: see text]. The advantage of this model lies in its ease of use and implementation since it could be applied with the knowledge of only one main sorption curve by considering [Formula: see text], in other words, we only use the axisymmetric property here. In the case where the other main sorption curve is known, we use this curve to incorporate the homotopy property in order to calibrate the parameter [Formula: see text].The full version of the proposed model is called Axisymmetric + Homotopic. Furthermore, it was compared not only with the experimental sorption curves of different types of materials but also with a model that is well known in the literature (CARMELIET’s model). This comparison shows that the Axisymmetric + Homotopic model reliably predicts hysteresis loops of various types of materials even with the knowledge of only one of the main sorption curves. However, the full version of Axisymmetric + Homotopic model is more reliable and covers a large range of materials. The proposed model was incorporated into the mass transfer model. The simulation results strongly match the experimental ones.

International audience; Thanks to the use of filters collected daily in the west of Paris, we confirm the passage of the lead-laden plume following the fire on the roof and spire of Notre-Dame Cathedral in April 2019. The measured concentrations on the filter (Pb = 1.4 μg m–3), scanning electron microscopy and Hysplit simulation, correspond to an estimate of a few hundred kilograms of lead that would have been volatilized and then oxidized in the form of micronic and submicronic aerosols. The concentrations found in the plume are, however, much lower than those found in the environment in the 1980s and 1990s but are 100 times higher than those found in times prior to and after the fire. The isotopic signature of the plume is almost identical to that of the fine Pb dust found inside the Notre-Dame building. It is different from the isotopic signature of the Parisian atmosphere before and after the fire, but it is similar to that of the atmospheric Pb legacy recorded by peat cores over the last 300 years in France. The presence of very fine lead-bearing particles makes them potentially transportable over long distances after large urban fires. Our study shows the value of daily aerosol sampling to retrospectively trace the plumes of air pollutants from industrial accidents but also from historical monument fires such as Notre-Dame in 2019.

Convergence zones are marked by a variety of settings that may follow each other in modern-day tectonics, including compressive phases such as subduction, obduction, collision but also extensive ones such as back-arc opening or stress-relaxation during orogenesis. Hence, the protracted evolution leading to a super-continent block amalgamation may be difficult to decipher and so may be the forcings on external enveloppes such as volcanism or erosion caused by the different phases.This question arises critically at the time of the Pan-African Orogenesis (1-0.5 Ga) assembling Gondwana, a time of supposedly dramatic and diachronical changes for external envelopes: glaciations of debated scales, deposition of various Banded Iron Formations, first (Ediacarian) fauna, replacement by Cambrian faunas. Our goal is to explore in detail the geodynamical succession leading to the amalgamation of blocks along the northern margin of the West African Craton (WAC), outcropping in the Central Anti-Atlas region, Morocco. This region is characterized by the occurrence of extended convergence-related magmatism, ophiolite emplacement and basins fillings (including BIF) during Cryogenian and Ediacaran periods.Data obtained from compilation of cartographic work, whole-rock geochemistry and datation reveals a polyphased but still poorly constrained evolution through proxies of continentality (εNd) and of crustal thickness (Sr/Y ratio). We present new data spanning metamorphic petrology, basin stratigraphy, coupled datation and trace element analysis in detrital zircons in order to better understand the evolution of the geodynamic, magmatic and drainage systems. We propose a geodynamic scenario based on these data: Development of an early oceanic arc (760-720 Ma) with juvenile magmatic signature (3

International audience; Fault Detection and Diagnosis (FDD) are important tools to perform on-going monitoring of the systems and help in their building commissioning. An innovative method is investigated based on combined data-driven and knowledge-based approaches. This article presents the method. First phase, a so-called operating map of the system is built using dimension reduction method and numerical or experimental dataset. This map is composed of several regions corresponding to nominal operation and to specific faults. The second phase focuses on the FDD. The monitored data are projected on the map. According to the position, a clear and precise fault detection and diagnosis can be carried. The method is applied to an air handling unit. The map is built using data generated with a building simulation program. The reliability of the method is proven using experimental data of nominal and fault operation generated.

Citizenship as a Commodity – of Golden Passports and the European Union “Golden passport” schemes are increasingly gaining popularity around the world. Meanwhile, this trend has also reached the European Union. It now threatens to lead to a partial commercialisation of both national citizenship and the European citizenship. This contribution examines the evolution of national citizenship law through “golden passports” and addresses the question of the compatibility of such programs with the law of the European Union. It thereby reveals the difficulty of reconciling the sovereignty of member states in matters of nationality with the principle of sincere cooperation in the EU.

The estimation of wall thermal properties through an inverse problem procedure enables to increase the reliability of the model predictions for building energy efficiency. Nevertheless, it requires to define an experimental campaign to obtain on-site observations for existing buildings. The design of experiments enables to search for the optimal measurement plan that ensure the highest precision of the parameter estimation. For on-site measurement in buildings, it seeks an answer to several questions such as number and position of sensors, period and duration of the experimental campaign. In this article, the Optimal Experiment Design (OED) methodology is applied for a multi-layer building wall to resolve the aforementioned issues.

The Moroccan Anti-Atlas orogenic belt encloses several Precambrian inliers comprising two major Neoproterozoic ophiolitic complexes: the Sirwa and Bou Azzer ophiolites. These ophiolites expose crustal and mantle units, thrusting over fragments of a long-lived intra-oceanic arc system. We present a detailed geochronological and petro-geochemical study of three mafic/ultramafic units of these two ophiolites: the Khzama sequence (Sirwa ophiolite) and the Northern and Southern Aït Ahmane sequences (Bou Azzer ophiolite). The crystallization of layered metagabbros from the Bou Azzer ophiolite (North Aït Ahmane sequence) has been dated here at 759 ± 2 Ma (U-Pb on zircons). This new age for the Bou Azzer ophiolite is similar to the formation of the Sirwa ophiolite (762 Ma) and suggests that both units formed during the same spreading event. Metabasalts of the three units show tholeiitic signature but with variable subduction-related imprints marked by LILE enrichments, HFSE depletions and variable Ti contents, similar to modern back-arc basin basalts (BABB). Their back-arc origin is also supported by the geochemical signature of ultramafic units showing very low contents in major and trace incompatible elements (Al2O3: 0.12–1.53 wt%, Ti: 3.5–64.2 ppm and Nb: 0.004–0.10 ppm), attesting of a highly refractory protolith. This is in agreement with the high Cr (0.44–0.81) and low to intermediate Mg (0.25–0.73) of their constitutive Cr-spinels. Dynamic melting models suggest that these serpentinites experienced intense and polyphased hydrous melting events, strongly influenced by supra-subduction zone SSZ-fluid influx and subduction-related melt percolation. Being particularly affected by these SSZ-melt/rock interactions and closer to arc units to the south, the Sirwa ophiolite and the South Aït Ahmane unit of the Bou Azzer ophiolite likely represent an early stage of the arc-back-arc system, which has been more influenced by the magmatic products of the arc activity compared to the North Aït Ahmane unit of the Bou Azzer ophiolite., SCOPUS: ar.j, info:eu-repo/semantics/published

The mafic-ultramafic Ougda magmatic complex is located in the west part of Tuarge Shield, in Algeria, between Tassendjanet terrane in the east and Ahnet terrane in the west. It is composed of three successive generations of magmatic rocks (Dostal et al., 1996). The first generation located in the north, includes ultramafic rocks cut by dikes of cumulate garnet-bearing mafic rocks and quartz diorite sheets. It records high-temperature metamorphic conditions, granulite facies. The second and third generation located in the south, includes undeformed cumulate and non-cumulate gabbros and intermediate to mafic dikes. The three generations record a geochemical evolution from tholeiitic to calco-alkaline magmatism with subduction-related oceanic environment (Dostal et al., 1996). The age of the first generation is around 800 Ma and the second generation is dated at 680 Ma, considered as the ages of the inception to demise of the oceanic lithosphere (Dostal et al., 1996; Caby and Monié, 2003). Here, we focus on garnet-bearing rocks that show particular interest, as they are affected by high-grade metamorphism in this area. Understanding the pressure-temperature (P-T) evolution of those garnet-bearing rocks allow a crucial constrain of the evolution of the oceanic crust in this area during the Panafrican orogeny.Petrographical investigation shows that all samples share similar mineralogical assemblages with garnet, plagioclase, amphibole, clinopyroxene, ilmenite and rutile. It is interpreted as typical of granulite facies. Garnet is the most dominate phase and show different textural types: Pokioblastic garnet with inclusions of amphibole, clinopyroxene, plagioclase, ilmenite and rutile. In some samples, garnet is very large (~2 cm), ilmenite is observed in garnet core and rutile appears with ilmenite in garnet rims. Clinopyroxene in garnet is a primary phase as it is surrounded by amphibole, which indicate a reaction with garnet. Garnet corona is around clinopyroxene and plagioclase and both are not in contact with each other. Modeling phase relationship using P-T pseudosections was calculated to constrain the P-T conditions and mineralogical evolution. For garnet growth, modal calculations with observed mineral assemblages are more consistent with a solid-state reaction where clinopyroxene and plagioclase are consumed to produce garnet. The PT path manifest with either cooling at high pressure or pressure increase stage, linked to garnet growth, 14-7 Kbar and 1000-700 °C. The P-T conditions are limited by the appearance of biotite at low temperature, solidus at high temperature and olivine at low pressure. The maximum pressure being recorded by rutile-ilmenite-bearing assemblage. This granulitisation stage is followed by a decompression in subsolidus conditions, amphibolites facies, where amphibole appears either as the product of clinopyroxene transformation or reaction between primary clinopyroxene and garnet through hydration. Lastly, hydration in low grade, greenschist facies, is recorded in garnet- and clinopyroxene-free domains with hydrous phases, chlorite, epidote and amphibole. Hence, P-T evolution recorded in garnet-bearing rocks of Ougda shows an anticlockwise PT path with granulitisation stage showing P-T peak recorded by rutile-ilmenite-bearing assemblage in garnet. Followed by a decompression in amphibolite facies with production of amphibole and ended up with late hydration in geenschist facies.

The design of numerical tools to model the behavior of building materials is a challenging task. The crucial point is to save computational cost and maintain high accuracy of predictions. There are two main limitations on the time scale choice, which put an obstacle to solve the above issues. First one is the numerical restriction. A number of research is dedicated to overcome this limitation and it is shown that it can be relaxed with innovative numerical schemes. The second one is the physical restriction. It is imposed by properties of a material, phenomena itself and corresponding boundary conditions. This work is focused on the study of a methodology that enables to overcome the physical restriction on the time grid. So-called Average Reduced Model (ARM) is suggested. It is based on smoothing the time-dependent boundary conditions. Besides, the approximate solution is decomposed into average and fluctuating components. The primer is obtained by integrating the equations over time, whereas the latter is an user-defined empirical model. The methodology is investigated for both heat diffusion and coupled heat and mass transfer. It is demonstrated that the signal core of the boundary conditions is preserved and the physical restriction can be relaxed. The model proved to be reliable, accurate and efficient also in comparison with the experimental data of two years. The implementation of the scarce time-step of $1 \, \sf{h}$ is justified. It is shown, that by maintaining the tolerable error it is possible to cut computational effort up to almost four times in comparison with the complete model with the same time grid.

International audience; In this paper, the spectral method is developed as a reduced-order model for the solution of parametric problems within the building refurbishment framework. We propose to use the spectral reduced-order method to solve parametric problems in an innovative way, integrating the unknown parameter as one of the coordinates of the decomposition. The residual is minimized combining the Tau–Galerkin method with the Collocation approach. The developed method is evaluated in terms of accuracy and reduction of the computational time in three different cases. The dynamic behaviour of unidimensional moisture diffusion is investigated. The cases focus on solving parametric problems in which the solution depends on space, time, diffusivity and material thickness. Results highlight that the parametric spectral reduced-order method provides accurate solutions and can reduce 10 times the degree of freedom of the solution. It allows efficient computation of the physical phenomena with a lower error when compared to traditional approaches

International audience; In this article, both numerical and experimental investigations were carried out on the durability of hemp concrete. For this, an accelerated aging process was performed using cycles of immersion, freezing and drying. Then, an experimental campaign was enabled to determine heat and mass transfer properties, as well as the microstructure for both aged and reference materials. Observations using a digital microscope showed the appearance of cracks at the interfaces and an increase of the porosity of about 6%. These microstructural modifications imply a non-negligible evolution of heat and mass transfer properties. Thus, a numerical model for the prediction of heat and mass transfer was developed. The prediction of physical phenomena was computed using both aged and reference material properties. It highlights the aging effects on the behaviour of the hemp concrete. The numerical simulation results showed significant discrepancies between the predicted relative humidity values for the two configurations (aged and reference) of about 18% and a maximum phase shift of 40 min, due to the amplification of the mass transfer kinetics after aging. Nevertheless, few deviations in temperature values were found. Thus, after aging, sensible heat fluxes were overestimated compared to the reference case, unlike latent heat fluxes, where an underestimation was shown.

Within the framework of building energy assessment, this article proposes to use a derivative based sensitivity analysis of heat transfer models in a building envelope. Two, global and local, estimators are obtained at low computational cost, to evaluate the influence of the parameters on the model outputs. Ranking of these estimators values allows to reduce the number of model unknown parameters by excluding non-significant parameters. A comparison with variance and regression-based methods is carried out and the results highlight the satisfactory accuracy of the continuous-based approach. Moreover, for the carried investigations the approach is $100$ times faster compared to the variance-based methods. A case study applies the method to a real-world building wall. The sensitivity of the thermal loads to local or global variations of the wall thermal is investigated. Additionally, a case study of wall with window is analyzed.

International audience; A suite of mafic pyroxenite xenoliths and clinopyroxene megacrysts was brought to the surface by Cenozoic nephelinites of the Jbel Saghro Volcanic Field (Anti-Atlas, Morocco). The large population of samples was subdivided into five groups: (i) clinopyroxenites sensu stricto; (ii) olivine clinopyroxenites; (iii) mica-bearing clinopyroxenites; (iv) kaersutite-bearing clinopyroxenites; (v) clinopyroxene megacrysts. These xenoliths display a cumulate texture (adcumulate, heteradcumulate with poikilitic clinopyroxene including olivine). The clinopyroxenes have the composition of augite and show an appreciable variation of MgO (7.02–14.80 wt.%), TiO2 (0.58–5.76 wt.%) and Al2O3 (2.81–12.38 wt.%) contents in grains. The clinopyroxenes are characterized by convex upward chondrite-normalized REE patterns, they display very similar trace element compositions with low contents of incompatible elements such as Rb (0−0.9 ppm), Ba (0.1–8.3 ppm), Th (0.1−0.3 ppm), U (0.01−0.04 ppm) and Nb (1.3–3.2 ppm). REE contents of the calculated melts in equilibrium with the clinopyroxene megacrysts and clinopyroxene from pyroxenite xenoliths are similar to those of the nephelinites exposed in Jbel Saghro. Crystallization temperatures of pyroxenite xenoliths and clinopyroxene megacrysts range from 950 °C to 1150 °C. Clinopyroxene barometry yielded pressure of crystallization ranging from 0.4 to 0.8 GPa for pyroxenite xenoliths and 0.3 to 0.7 GPa for clinopyroxene megacrysts. This pressure range is in agreement with pyroxenite xenoliths and clinopyroxene megacrysts being crystallized from their parental melts at the lower and upper crust.

Predictions of physical phenomena in buildings are carried out by using physical models formulated as a mathematical problem and solved by means of numerical methods, aiming at evaluating, for instance, the building thermal or hygrothermal performance by calculating distributions and fluxes of heat and moisture transfer. Therefore, the choice of the numerical method is crucial since it is a compromise among (i) the solution accuracy, (ii) the computational cost to obtain the solution and (iii) the complexity of the method implementation. An efficient numerical method enables to compute an accurate solution with a minimum computational run time (CPU). On that account, this article brings an investigation on the performance of three numerical methods. The first one is the standard and widely used finite-difference approach, while the second one is the so-called RC approach, which is a particular method brought to the building physics area by means of an analogy of electric circuits. The third numerical method is the spectral one, which has been recently proposed to solve nonlinear diffusive problems in building physics. The three methods are evaluated in terms of accuracy on the assessment of the dependent variable (temperature or vapor pressure) or of density of fluxes for three different cases: i) heat diffusion through a concrete slab, ii) moisture diffusion through an aerated concrete slab and iii) heat diffusion using measured temperatures as boundary conditions. Results highlight the spectral approach as the most accurate method. The RC based model with a few number of resistances does not provide accurate results for temperature and vapor pressure distributions neither to flux densities nor conduction loads., 35 pages, 19 figures, 2 tables, 42 references. Other author's papers can be downloaded at http://www.denys-dutykh.com/

International audience; This work provides the first comprehensive petrological and multi-scale structural investigation of a suite of ultramafic bodies and enclosing metasediments from the Late Paleozoic accretionary prism of South-Central Chile. The targeted outcrops are located in the La Cabaña area and are characterized by the presence of three main types of ultramafic rocks: (1) partially serpentinized massive peridotites, (2) antigoritic schistose serpentinites, and (3) antigoritic mylonitic serpentinites. Partially serpentinized massive peridotites and schistose serpentinites recorded a common first hydration event with the formation of Fe2+ porous rim in chromites (at ~500 °C), followed by static partial transformation of olivine to lizardite (below ~300 °C) and formation of rims of Fe3+-rich chromite and magnetite around chromites. A second event of serpentinization linked to fluid passage through zones with focused deformation resulted in the partial transformation of partially lizarditized massive peridotites into antigoritic schistose serpentinites (at ~320–400 °C). This second event took place within the shallower portion of the serpentinitic subduction channel, near the base of the accretionary prism and was characterized by the formation of tubular folds made up of lenses of olivine-lizardite massive rocks embedded in a matrix of schistose serpentinites. Antigoritic mylonitic serpentinites encountered in the matrix of schistose serpentinites may locally contain metamorphic olivine (i.e., olivine-bearing mylonitic serpentinites), registering higher temperature conditions at medium pressures (~600 °C, 11 kbar) that prevailed during the initial immature stage of development of the subduction system. Moreover, some mylonitic serpentinites containing Ti-clinohumite, Ti-chondrodite and metamorphic olivine still record higher pressure conditions (>15 kbar, i.e., >50 km depth for ~500 °C), which are related with a deformational event taking place when the subduction system had already cooled. These medium- and high-P mylonitic serpentinites preserved kinematic indicators of burial, whereas their exhumation along the subduction channel towards the shallower schistose serpentinites near the base of the accretionary prism could take place through discrete shear zones possibly aided by large sheath folds. Once incorporated in the accretionary prism (c. 285 Ma ago), the serpentinites shared metamorphism and deformation with the enclosing metasediments. Subvertical shortening related to uplift processes within the accretionary system took place in the stability field of antigorite (>300 °C) and, later, a subhorizontal E-W shortening prevailed in more superficial conditions.

The goal of this study is to propose an efficient numerical model for the predictions of capillary adsorption phenomena in a porous material. The Scharfetter-Gummel numerical scheme is proposed to solve an advection-diffusion equation with gravity flux. Its advantages such as accuracy, relaxed stability condition, and reduced computational cost are discussed along with the study of linear and nonlinear cases. The reliability of the numerical model is evaluated by comparing the numerical predictions with experimental observations of liquid uptake in bricks. A parameter estimation problem is solved to adjust the uncertain coefficients of moisture diffusivity and hydraulic conductivity., Comment: 41 pages, 19 figures, 3 tables, 35 references. Other author's papers can be downloaded at http://www.denys-dutykh.com/

International audience; The 1000 km-long suture zone of the Dahomeyide belt, exposed from Southeast Ghana to South Mali, corresponds to a narrow and lithologically diverse area with symptomatic coronitic HP granulitic massifs. Based on a review of published petrological, geochemical and geochronological data along the Dahomeyide belt we propose a global scenario for the closure of the Pharusian ocean between the West African craton (WAC) and the Benino-Nigerian shield during the end of the Neoproterozoic. The onset of a long-lived oceanic subduction by 800–780 Ma is recorded by early magmatism in the Amalaoulaou intra-oceanic arc in Mali, contemporary to the Gourma and Adrar des Iforas to the North, and in Brazil to the South. The first occurrence of tonalitic plutons dated at 720 Ma, and the development of a forearc system around 650 Ma mark the onset of active margin subduction beneath the Benino-Nigerain shield and its northward prolongation in Mali. Oceanic subduction beneath the active margin ended between 640 and 630 Ma with the onset of subduction of the WAC continental margin while subduction related magmatism continues till ca. 600 Ma on the upper plate. During a short period between 620 and 610 Ma, the forearc system and the tip of the active continental margin were buried synchronously. The positive Bouguer anomaly observed to the East of the suture zone, in Benin, and not beneath the suture zone itself supports the occurrence of a massive mafic body at the base of the crust that could correspond to the underplated buried forearc. Ultimately, the exhumation and partial amphibolitization of the suture zone and a shift from a calc-alkaline magmatism to anatectic magmatism along with the onset of strike-slip faulting in the upper plate marks the transition from continental subduction to continental collision between 610 and 580 Ma. This work highlights the importance of the Pharusian suture zone s.l. To our knowledge, it represents a unique example in the world in where the forearc system is buried and partly exhumed at the transition from subduction to collision.