46 results on '"Berger, Julien"'
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2. Estimation of ground thermal diffusivity using the conjugate gradient method with adjoint problem formulation
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Karashbayeva, Zhanat, Berger, Julien, Orlande, Helcio R.B., and Rysbaiuly, Bolatbek
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- 2023
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3. A state-space model to control an adaptive facade prototype using data-driven techniques
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Jumabekova, Ainagul, Berger, Julien, Hubert, Tessa, Dugué, Antoine, Vogt Wu, Tingting, Recht, Thomas, and Inard, Christian
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- 2023
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4. Assessing the wall energy efficiency design under climate change using POD reduced order model
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Berger, Julien, Allery, Cyrille, and Machard, Anaïs
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- 2022
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5. Formation of the Nkob talc deposit by contact metamorphism and fluid infiltration into siliceous dolostones (Moroccan Anti-Atlas)
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Chatir, Adil, Berger, Julien, Ennih, Nasser, Triantafyllou, Antoine, de Parseval, Philippe, Errami, Ezzoura, Diot, Hervé, Baele, Jean-Marc, Mohsine Aghzer, Abdel, Monnier, Christophe, and Boutaleb, Mohammed
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- 2022
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6. U-Pb-Hf isotopic systematics of zircons from granites and metasediments of southern Ouaddaï (Chad), implications for crustal evolution and provenance in the Central Africa Orogenic Belt
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Djerossem, Felix, Zeh, Armin, Isseini, Moussa, Vanderhaeghe, Olivier, Berger, Julien, and Ganne, Jérôme
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- 2021
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7. Episodic magmatism during the growth of a Neoproterozoic oceanic arc (Anti-Atlas, Morocco)
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Triantafyllou, Antoine, Berger, Julien, Baele, Jean-Marc, Mattielli, Nadine, Ducea, Mihai N., Sterckx, Sarane, Samson, Scott, Hodel, Florent, and Ennih, Nasser
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- 2020
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8. Weather-based indicators for analysis of moisture risks in buildings
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Morishita, Claudia, Berger, Julien, and Mendes, Nathan
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- 2020
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9. Tectono-metamorphic evolution of subduction channel serpentinites from South-Central Chile
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Plissart, Gaëlle, González-Jiménez, José M., Garrido, Leonardo N.F., Colás, Vanessa, Berger, Julien, Monnier, Christophe, Diot, Hervé, and Padrón-Navarta, José Alberto
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- 2019
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10. The effects of high-temperature fractional crystallization on calcium isotopic composition
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Valdes, Maria C., Debaille, Vinciane, Berger, Julien, and Armytage, Rosalind M.G.
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- 2019
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11. The Marbat metamorphic core-complex (Southern Arabian Peninsula): Reassessment of the evolution of a Neoproterozoic island-arc from petrological, geochemical and U-Pb zircon data
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Barbey, Pierre, Denèle, Yoann, Paquette, Jean-Louis, Berger, Julien, Ganne, Jérôme, and Roques, Damien
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- 2018
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12. 2D whole-building hygrothermal simulation analysis based on a PGD reduced order model
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Berger, Julien, Mazuroski, Walter, Mendes, Nathan, Guernouti, Sihem, and Woloszyn, Monika
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- 2016
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13. Proper Generalised Decomposition for heat and moisture multizone modelling
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Berger, Julien, Guernouti, Sihem, Woloszyn, Monika, and Chinesta, Francisco
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- 2015
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14. Extreme trace elements fractionation in Cenozoic nephelinites and phonolites from the Moroccan Anti-Atlas (Eastern Saghro)
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Berger, Julien, Ennih, Nasser, and Liégeois, Jean-Paul
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- 2014
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15. Continental subduction recorded by Neoproterozoic eclogite and garnet amphibolites from Western Hoggar (Tassendjanet terrane, Tuareg Shield, Algeria)
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Berger, Julien, Ouzegane, Khadidja, Bendaoud, Abderrahmane, Liégeois, Jean-Paul, Kiénast, Jean-Robert, Bruguier, Olivier, and Caby, Renaud
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- 2014
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16. Petrogenesis of Archean PGM-bearing chromitites and associated ultramafic–mafic–anorthositic rocks from the Guelb el Azib layered complex (West African craton, Mauritania)
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Berger, Julien, Diot, Hervé, Lo, Khalidou, Ohnenstetter, Daniel, Féménias, Olivier, Pivin, Marjorie, Demaiffe, Daniel, Bernard, Alain, and Charlier, Bernard
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- 2013
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17. Thermodynamic analysis of the effect of mass transfer on a real building wall efficiency under climatic transient conditions.
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Berger, Julien, Ferrasse, Jean-Henry, Gasparin, Suelen, Metayer, Olivier Le, and Kadoch, Benjamin
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MASS transfer , *THERMODYNAMIC laws , *CLIMATE change , *HEAT transfer , *HEAT transfer coefficient , *COMBINED cycle power plants , *WALLS - Abstract
Within the environmental context, designing energy efficient buildings is crucial. Standard performance indicators evaluate the quantity of energy going through the wall. Such indicator considers the energy balance of the wall, i.e the first thermodynamic law. However, the main drawback of such approach is that it does not qualify the energy quality, which can be done by the second thermodynamic law. This paper proposed a performance indicator that both quantifies and qualifies the energy efficiency of a wall. It is based on the evaluation of the exergy destruction rate. The performance indicator has been developed for transient conditions induced by climatic variations of temperature and relative humidity and considering coupled heat and mass transfer in the wall. Calculations were carried out with experimental data obtained from a wall demonstrator under climatic conditions and comparisons with standard performance indicators were also performed. The corresponding results highlighted that the exergy loss allows a more accurate assessment of the energy performance and the influence of mass transfer on it. Indeed, the mass transfer can account for 30% in the exergy destruction. [ABSTRACT FROM AUTHOR]
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- 2024
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18. Origin of micro-layering in a deep magma chamber: Evidence from two ultramafic–mafic layered xenoliths from Puy Beaunit (French Massif Central)
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Féménias, Olivier, Ohnenstetter, Daniel, Coussaert, Nicolas, Berger, Julien, and Demaiffe, Daniel
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- 2005
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19. Shape optimization of the energy efficiency of building retrofitted facade.
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Alpar, Sultan, Berger, Julien, Mazuroski, Walter, and Belarbi, Rafik
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STRUCTURAL optimization , *ENERGY consumption , *BOUNDARY element methods , *BUILDING envelopes , *THERMAL insulation , *EXTERIOR walls - Abstract
The current state of research indicates a necessity of further examination in both numerical and experimental studies related to optimizing shapes of building enclosures for the enhancement of their energy efficiency. The demand for research primarily arises due to the numerical complexities associated with optimizing shapes for this specific purpose. Consequently, the primary objective of this article is to address and bridge these gaps in the field. To achieve this, a two-dimensional steady-state heat diffusion model is assumed to represent the physical processes occurring within building facades of varying shapes. A third type boundary condition is applied to the exterior boundary, encompassing convective and incident short-wave solar radiation effects. The calculation of short-wave radiation accounts for factors such as sunlight exposure and shading, influenced by the surrounding urban environment. The internal boundary interfaces with the indoor ambient air, and thus, a Robin boundary condition is adopted. To tackle the computational demands while ensuring accuracy, the boundary element method (BEM) is employed by discretizing the domain boundary into discrete elements. Then, two heat transfer design objectives are define according to the period of investigations: ones related to enhancing heat transfer and ones focused on thermal insulation problem. Last, a real-world case study is conducted, considering a house wall under varying climate conditions throughout the year. Optimal shapes for the external wall boundary are determined with the constraint that the optimized facade utilizes the same amount of material as the reference flat one. The results demonstrate a substantial increase in energy efficiency compared to the reference flat wall case. • Shape optimization of building facade • Short wave radiation • Steady-state heat transfer • Boundary element method • Energy efficiency [ABSTRACT FROM AUTHOR]
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- 2024
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20. Estimation of soils thermophysical characteristics in a nonlinear inverse heat transfer problem.
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Alpar, Sultan, Berger, Julien, Rysbaiuly, Bolatbek, and Belarbi, Rafik
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HEAT transfer , *NONLINEAR equations , *THERMOPHYSICAL properties , *SOIL classification , *SOILS - Abstract
It is well known that knowledge of thermophysical parameters is a leading strategy to research effects of energy transfer in soils. The present article proposes an inverse analysis for numerical solving of nonlinear heat transfer problem to determine the thermophysical properties of two different soil types: sand and chernozem. First, estimation of thermophysical parameters is performed using temperature data from experimental set-up, which is two-chambered container for two soil types. Second, numerical algorithm is based on implicit Euler scheme for discretization, Newton method to solve nonlinear system of equations and Levenberg-Marquardt method to minimize nonlinear estimator with Tikhonov's regularization technique. Simulations have been efficiently carried out for two different soil types, showing that the reliability of the model is satisfying with a discrepancy between numerical predictions and experimental observations remaining within the measurement error. • Estimation of two soil types thermophysical properties. • Reliability of the model is satisfying. • Experimental set-up is used for parameters estimation. • Sensitivity coefficients by direct differentiation. • Robustness of calculation. [ABSTRACT FROM AUTHOR]
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- 2024
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21. A new model for simulating heat, air and moisture transport in porous building materials.
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Berger, Julien, Dutykh, Denys, Mendes, Nathan, and Rysbaiuly, Bolatbek
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HEAT transfer , *POROUS materials , *MOISTURE in building materials , *COMPUTER simulation , *MASS transfer - Abstract
Highlights • A detailed mathematical model for the heat, air and mass transfer is achieved. • An efficient numerical model is proposed to save computational efforts. • Demonstration of numerical model efficiency (cpu time, accuracy) for a case study. • Evaluation of the reliability of the model by confronting to experimental results. Abstract This work presents a detailed mathematical model combined with an innovative efficient numerical model to predict heat, air and moisture transfer through porous building materials. The model considers the transient effects of air transport and its impact on the heat and moisture transfer. The achievement of the mathematical model is detailed in the continuity of L uikov 's work. A system composed of two advection–diffusion differential equations plus one exclusively diffusion equation is derived. The main issue to take into account the transient air transfer arises in the very small characteristic time of the transfer, implying very fine discretisation. To circumvent these difficulties, the numerical model is based on the D u F ort –F rankel explicit and unconditionally stable scheme for the exclusively diffusion equation. It is combined with a two–step R unge –K utta scheme in time with the S charfetter –G ummel numerical scheme in space for the coupled advection–diffusion equations. At the end, the numerical model enables to relax the stability condition, and, therefore, to save important computational efforts. A validation case is considered to evaluate the efficiency of the model for a nonlinear problem. Results highlight a very accurate solution computed about 16 times faster than standard approaches. After this numerical validation, the reliability of the mathematical model is evaluated by comparing the numerical predictions to experimental observations. The latter is measured within a multi-layered wall submitted to a sudden increase of vapor pressure on the inner side and driven climate boundary conditions on the outer side. A very satisfactory agreement is noted between the numerical predictions and experimental observations indicating an overall good reliability of the proposed model. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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22. An adaptive simulation of nonlinear heat and moisture transfer as a boundary value problem.
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Gasparin, Suelen, Berger, Julien, Dutykh, Denys, and Mendes, Nathan
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COMPUTER simulation of heat transfer , *MOISTURE in building materials , *POROUS materials , *DIFFUSION , *BOUNDARY value problems , *DISCRETIZATION methods , *ORDINARY differential equations , *INITIAL value problems - Abstract
This work presents an alternative view on the numerical simulation of diffusion processes applied to the heat and moisture transfer through porous building materials. Traditionally, by using the finite-difference approach, the discretization follows the Method Of Lines (MOL), when the problem is first discretized in space to obtain a large system of coupled Ordinary Differential Equations (ODEs). Thus, this paper proposes to change this viewpoint. First, we discretize in time to obtain a small system of coupled ODEs, which means instead of having a Cauchy (Initial Value) Problem (IVP), we have a Boundary Value Problem (BVP). Fortunately, BVPs can be solved efficiently today using adaptive collocation methods of high order. To demonstrate the benefits of this new approach, three case studies are presented, in which one of them is compared with experimental data. The first one considers nonlinear heat and moisture transfer through one material layer while the second one considers two material layers. Results show how the nonlinearities and the interface between materials are easily treated, by reasonably using a fourth-order adaptive method. Finally, the last case study compares numerical results with experimental measurements, showing a good agreement. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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23. A mixed POD–PGD approach to parametric thermal impervious soil modeling: Application to canyon streets.
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Azam, Marie-Hélène, Guernouti, Sihem, Musy, Marjorie, Poullain, Philippe, Berger, Julien, and Rodler, Auline
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URBAN soils ,SOILS ,ORTHOGONAL decompositions ,URBAN heat islands ,HEAT transfer ,MICROCLIMATOLOGY ,PARAMETRIC modeling ,MATHEMATICAL models - Abstract
Highlights • We propose a parametric model dedicated to urban soil thermal modeling. • A combination of two reduced-order methods, i.e. POD and PGD, is presented. • Calculated temperatures are evaluated with respect to in situ measurements. • The parametric soil model is coupled with the
SOLENE-microclimat tool. • Its accuracy and computational cost are evaluated in an urban setting. Abstract Numerical simulation is a powerful tool for assessing the causes of an Urban Heat Island (UHI) effect or quantifying the impact of mitigation solutions on local climatic conditions. However, the numerical cost associated with such a tool is quite significant at the scale of an entire district. Today, the main challenge consists of achieving both a proper representation of the physical phenomena and a critical reduction in the numerical costs of running simulations. This paper presents a combined parametric urban soil model that accurately reproduces thermal heat flux exchanges between the soil and the urban environment with a reduced computational time. For this purpose, the use of a combination of two reduced-order methods is proposed herein: the Proper Orthogonal Decomposition method, and the Proper Generalized Decomposition method. The developed model is applied to two case studies in order to establish a practical evaluation: an open area independent of the influences of the surrounding surface, and a theoretical urban scene with two canyon streets. The error due to the model reduction remains below 0.2 °C on the mean surface temperature for a reduced computational cost of 80%. Compared to in situ measurements the error remains bellow 1.24 °C at the surface. [ABSTRACT FROM AUTHOR]- Published
- 2018
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24. Analysis and improvement of the VTT mold growth model: Application to bamboo fiberboard.
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Berger, Julien, Le Meur, Hervé, Dutykh, Denys, Nguyen, Dang Mao, and Grillet, Anne-Cécile
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FIBERBOARD ,BAMBOO ,HUMIDITY ,MOLDS (Fungi) ,TEST reliability - Abstract
The reliability of a model is its accuracy in predicting the physical phenomena using the known input parameters. It also depends on the model's ability to estimate relevant parameters using observations of the physical phenomena. In this paper, the reliability of the VTT model is investigated under these two criteria for various given temperature and relative humidity constant in time. First of all, experiments are conducted on bamboo fiberboard. Using these data, five parameters of the VTT model, defining the mold vulnerability class of a material, are identified. The results highlight that the determined parameters are not within the range of the classes defined in the VTT model. In addition, the quality of the parameter estimation is not satisfactory. Then the sensitivity of the numerical results of the VTT model is analyzed by varying an input parameter. These investigations show that the VTT mathematical formulation of the physical model of mold growth is not reliable. An improved model is proposed with a new mathematical formulation. It is inspired by the logistic equation whose parameters are estimated using the experimental data obtained. The parameter estimation is very satisfactory. In the last parts of the paper, the numerical predictions of the improved model are compared to experimental data from the literature to prove its reliability. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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25. Dynamic experimental method for identification of hygric parameters of a hygroscopic material.
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Busser, Thomas, Berger, Julien, Piot, Amandine, Pailha, Mickael, and Woloszyn, Monika
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PERMEABILITY ,MOISTURE ,NUMERICAL analysis ,HUMIDITY ,HYGROTHERMOELASTICITY - Abstract
The standard methods to determine the vapour permeability and the moisture sorption curve may lack of accuracy since discrepancies are observed when comparing numerical predictions to experimental data. Moreover, these properties are determined in steady state conditions while the numerical predictions are carried in transient regime. Thus, this paper presents an experimental design to estimate these properties using dynamic measurements and identification method. The experimental facility is presented, enabling to measure at the same time the relative humidity within the material and the total moisture content. The performance of the facility and protocol in terms of reproducibility, uncertainty and direction of heat and moisture transfers are checked, confirming the abilities of the set-up. Then, experimental results are used to determine the hygrothermal material properties using a trust-region algorithm. Investigations are done to analyse important issues as the choice of the observation: relative humidity and/or mass measurements, to solve the parameter estimation problem. The estimated properties are finally validated by comparing the numerical predictions with experimental data for other boundary conditions. [ABSTRACT FROM AUTHOR]
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- 2018
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26. On the estimation of moisture permeability and advection coefficients of a wood fibre material using the optimal experiment design approach.
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Berger, Julien, Busser, Thomas, Dutykh, Denys, and Mendes, Nathan
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PERMEABILITY , *POROUS materials , *EXPERIMENTAL design , *MOISTURE , *BOUNDARY value problems , *FIBERS - Abstract
This paper presents a practical application of the concept of Optimal Experiment Design (OED) for the determination of properties of porous materials with in situ measurements and an identification method. First, an experimental set-up was presented and used for the measurement of relative humidity within a wood fibre material submitted to single and multiple steps of relative humidity variation. Then, the application of OED enabled to plan the experimental conditions in terms of sensor positioning and boundary conditions out of 20 possible designs. The OED search was performed using the Fisher information matrix and a priori knowledge of the parameters. It ensures to provide the best accuracy of the identification method and thus the estimated parameter. Optimal design results have been found for single steps from the relative humidity ϕ = 10–75%, with one sensor located at the position X between 4 and 6 cm, for the estimation of moisture permeability coefficients, while from ϕ = 75 % to ϕ = 33 % , with one sensor located at X ∘ = 3 cm , for the estimation of the advection coefficient. The OED has also been applied for the identification of couples of parameters. A sample submitted to multiple relative humidity steps ( ϕ = 10–75–33–75%) with a sensor placed at X ∘ = 5 cm was found as the best option for determining both properties with the same experiment. These OED parameters have then been used for the determination of moisture permeability and advection coefficients. The estimated moisture permeability coefficients are twice higher than the a priori values obtained using standard methods. The advection parameter corresponds to the mass average velocity of the order of v = 0.01 mm / s within the material and may play an important role on the simulation of moisture front. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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27. Accurate numerical simulation of moisture front in porous material.
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Berger, Julien, Gasparin, Suelen, Dutykh, Denys, and Mendes, Nathan
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POROUS materials ,COMPUTER simulation ,ADVECTION-diffusion equations ,DIFFERENTIAL equations ,NONLINEAR analysis - Abstract
When comparing measurements to numerical simulations of moisture transfer through porous materials a rush of the experimental moisture front is commonly observed in several works shown in the literature, with transient models that consider only the diffusion process. Thus, to overcome the discrepancies between the experimental and the numerical results, this paper proposes to include the moisture advection transfer in the governing equation. To solve the advection-diffusion or the so-called convection differential equation, it is first proposed two efficient numerical schemes whose efficiencies are investigated for both linear and nonlinear cases. The first scheme, Scharfetter – Gummel , presents a Courant-Friedrichs-Lewy (CFL) condition but it is more accurate and faster than the second one, the well-known Crank – Nicolson approach. Furthermore, the Scharfetter – Gummel scheme has the advantages of being well-balanced and asymptotically preserved. Then, to conclude, results of the convective moisture transfer problem obtained by means of the Scharfetter – Gummel numerical scheme are compared to experimental data from the literature. The inclusion of an advective term in the model may clearly lead to better results than purely diffusive models. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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28. An innovative method for the design of high energy performance building envelopes.
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Berger, Julien and Mendes, Nathan
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BUILDING envelopes , *BUILDING performance , *TECHNOLOGICAL innovations , *THERMAL insulation , *THERMAL diffusivity - Abstract
In this paper, an innovative method to minimise energy losses through building envelopes is presented, using the Proper Generalised Decomposition (PGD), written in terms of space x , time t , thermal diffusivity α and envelope thickness L . The physical phenomenon is solved at once, contrarily to classical numerical methods that cannot create a parameter dependent model. First, the PGD solution is validated with an analytical solution to prove its accuracy. Then a complex case study of a multi-layer wall submitted to transient boundary conditions is investigated. The parametric solution is computed as a function of the space and time coordinates, as well as the thermal insulation thickness and the load material thermal diffusivity. Physical behaviour and conduction loads are analysed for 76 values of thermal insulation thickness and 100 types of load material properties. Furthermore, the reduced computational cost of the PGD is highlighted. The method computes the solution 100 times faster than standard numerical approaches. In addition, the PGD solution has a low storage cost, providing interesting development of parametric solutions for real-time applications of energy management in buildings. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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29. On the optimal experiment design for heat and moisture parameter estimation.
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Berger, Julien, Dutykh, Denys, and Mendes, Nathan
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HEAT conduction , *MOISTURE measurement , *PARAMETER estimation , *POROUS materials , *BOUNDARY value problems , *EXPERIMENTAL design - Abstract
In the context of estimating material properties of porous walls based on in-site measurements and identification method, this paper presents the concept of Optimal Experiment Design (OED). It aims at searching the best experimental conditions in terms of quantity and position of sensors and boundary conditions imposed to the material. These optimal conditions ensure to provide the maximum accuracy of the identification method and thus the estimated parameters. The search of the OED is done by using the Fisher information matrix and a priori knowledge of the parameters. The methodology is applied for two case studies. The first one deals with purely conductive heat transfer. The concept of optimal experiment design is detailed and verified with 100 inverse problems for different experiment designs. The second case study combines a strong coupling between heat and moisture transfer through a porous building material. The methodology presented is based on a scientific formalism for efficient planning of experimental work that can be extended to the optimal design of experiments related to other problems in thermal and fluid sciences. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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30. Bayesian inference for estimating thermal properties of a historic building wall.
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Berger, Julien, Orlande, Helcio R.B., Mendes, Nathan, and Guernouti, Sihem
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THERMAL properties of buildings ,HISTORIC buildings ,THERMAL conductivity measurement ,HEAT convection ,ATMOSPHERIC temperature ,CALIBRATION ,TESTING - Abstract
In this paper, the use of Bayesian inference is explored for estimating both the thermal conductivity and the internal convective heat transfer coefficient of an old historic building wall. The room air temperature, as well as the temperatures at the surface and within the wall have been monitored during one year and then used to solve the identification problem. With Bayesian inference, the posterior distributions of the unknown parameters are explored based on their prior distributions and on the likelihood function that models the measurement errors. In this work, the Markov Chain Monte Carlo method is used to explore the posterior distribution. The error of the inadequacy of mathematical model are considered using the approximation error model. The distribution of the estimated parameters have a small standard deviation, which illustrates the accuracy of the method. The parameters have been compared to the standard values from the French thermal regulations. The heat flux at the internal surface has been calculated with the estimated parameters and the standard values. It is shown that the standard values underestimate the heat flux of an order by 10%. This study also illustrates the importance of the preliminary diagnosis of a building with the estimation of the thermal properties of the wall for model calibration. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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31. The Tachakoucht–Iriri–Tourtit arc complex (Moroccan Anti-Atlas): Neoproterozoic records of polyphased subduction-accretion dynamics during the Pan-African orogeny.
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Triantafyllou, Antoine, Berger, Julien, Baele, Jean-Marc, Diot, Hervé, Ennih, Nasser, Plissart, Gaëlle, Monnier, Christophe, Watlet, Arnaud, Bruguier, Olivier, Spagna, Paul, and Vandycke, Sara
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PROTEROZOIC Era , *SUBDUCTION , *ACCRETION disks , *OROGENY - Abstract
We report new mapping, tectonic, metamorphic and U–Pb zircon dating data on the polyphased Tachakoucht–Iriri and Tourtit arc-related units within the Moroccan Pan-African belt (Sirwa window, Anti-Atlas). The studied area contains four different sub-units, from south to north: (1) the Tachakoucht gneisses intruded to its northern part by (2) Iriri intrusions. To the north, the Tachakoucht–Iriri massif is thrusted by (3) the south-verging 760 Ma Khzama ophiolitic sequence intruded by (4) the Tourtit meta-granitic complex. The Tachakoucht gneiss represents former andesitic to dacitic porphyritic rocks crystallized around 740–720 Ma in an intra-oceanic arc setting (IOAS). Subsequently, it has been buried and metamorphosed to 700 °C, 8 kbar in response to early accretion of the arc onto the West African Craton (WAC). This tectono-metamorphic event also led to the dismembering and stacking of back-arc ophiolite onto the arc unit. Subsequently, the Iriri intrusions, a suite of hydrous mafic dykes (hornblende gabbro and fine-grained basalt) and ultramafic (hornblendite) plutons showing subduction zone affinities, intruded the Tachakoucht gneiss under P – T conditions of 750–800 °C and 2–5 kbar. Emplacement of Iriri intrusions led locally to pronounced partial melting of the Tachakoucht gneiss and to the production of leucogranitic melts. These melts crop out into the Iriri–Tachakoucht gneiss contacts as leucogneissic bands (former leucosomes, dated at 651 ± 5 Ma) but also intruded the Khzama ophiolite to form the Tourtit granite (dated at 651 ± 3 Ma). These ages (651–641 Ma) also constrain the timing of Iriri intrusion emplacement. The entire complex has been overprinted by a second deformation event under greenschist to amphibolite facies conditions marked by transposition of primary structures and a development of mylonitic shear zones. These results and those published on the Bou Azzer window show that two phases of subduction-related magmatism occurred in the Anti-Atlas belt and that they were separated by an early accretion of the intra-oceanic arc system (IOAS) onto the West African craton passive margin. Our interpretations also validate thermo-mechanical models predicting an intense perturbation of subduction dynamics during arc-continent collision ( i.e. composite subductions, polarity reversal) which can expand the production of typical hydrous arc magma and induces a late magmatic phase after partial or total accretion of the IOAS. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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32. New occurrence of UHP eclogites in Limousin (French Massif Central): Age, tectonic setting and fluid–rock interactions
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Berger, Julien, Féménias, Olivier, Ohnenstetter, Daniel, Bruguier, Olivier, Plissart, Gaëlle, Mercier, Jean-Claude C., and Demaiffe, Daniel
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ECLOGITE , *ZOISITE , *TRACE elements , *CYANITE , *CRYSTALLIZATION - Abstract
Abstract: Kyanite and zoisite eclogites from the Limousin area in the Variscan French Massif Central (FMC) have been formed by deep subduction to 100km depth at peak pressure–temperature conditions around 660°C and 2.9GPa. They belong to a thin tectonic unit comprising ophiolitic bodies devoid of HP-UHP markers and forming a transported suture zone now separating the two main lithotectonic units of the FMC with contrasted tectono-metamorphic features (namely the lower and upper allochthons). Composition of kyanite–eclogites is similar to supra-subduction-zone basalts found in back-arc basins or island arcs (LREE depleted, negative Nb–Ta anomalies, εNd: +6 to +9). Zoisite eclogites have the major-element fingerprint of ultrabasic iron-rich plagioclase cumulates common in continental intrusions or forming Fe–Ti oceanic gabbros. The distribution of immobile trace-elements is however more comparable to alkaline Si-undersaturated rocks, but the Sr–Nd isotopic composition (87Sr/86Sr: 0.706; εNd: −3 to −5) suggests the intervention of an old radiogenic crustal component during their petrogenesis. The chemical composition of hydrous zoisite eclogites does not correspond closely to a common magmatic precursor. It is thus suggested that, by analogy with well exposed worldwide HP-UHP terranes, at least a part of the trace-element signature and the isotopic compositions are controlled by channelled fluid–rock interaction at UHP conditions, leading to localised segregation of zoisite that hosts nearly all Sr and LREE budgets of the bulk eclogite. Sr–Nd isotopic composition of these samples is thus controlled by zoisite and probably represents the isotopic composition of the fluid phase present during UHP recrystallisation. Zircons extracted from a zoisite eclogite were dated in-situ by LA-ICP-MS. Crystallisation of the magmatic precursor is bracketed between 489 and 475Ma and the UHP event is dated at 412±10Ma, in agreement with published ages for the Eo-Variscan HP stage in the FMC. A late resetting of the U–Pb isotopic system at 382±7Ma is related to an anatectic high pressure–medium pressure event, well known in the Limousin area. The oceanic eclogites dated in this study are tentatively linked to the Galicia–South Brittany Lower Paleozoic Ocean; they show evidence of the existence of an intra-oceanic subduction zone at the Lower Ordovician and of partial closure of this oceanic domain by ocean–continent subduction during Early Devonian. [Copyright &y& Elsevier]
- Published
- 2010
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33. Pyroxenite xenoliths and clinopyroxene megacrysts from the Cenozoic Jbel Saghro Volcanic Field (Anti-Atlas, Morocco): Petrography, mineral chemistry and equilibration conditions.
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Soukrati, Abdelghani, Youbi, Nasrrddine, Grégoire, Michel, Berger, Julien, Boumehdi, Moulay Ahmed, Ibhi, Abderrahmane, and Chaham, Khalid Rkha
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INCLUSIONS in igneous rocks ,VOLCANIC fields ,PYROXENITE ,PETROLOGY ,TRACE elements ,CENOZOIC Era - Abstract
• Compositional diversity of pyroxenite xenoliths and clinopyroxene megacrysts in Saghro nephelinites is shown. • Mg-number and Cr 2 O 3 contents of clinopyroxene increase from kaersutite-bearing clinopyroxenites to olivine clinopyroxenites. • Chemical compositions of clinopyroxene are used to identify the parental melt of pyroxenite xenoliths and megacrysts. • Crystallization of pyroxenite xenoliths and clinopyroxene megacrysts at a wide range of pressure (0.3−0.8 GPa). 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.%), TiO 2 (0.58–5.76 wt.%) and Al 2 O 3 (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. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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34. Estimation of the thermal properties of an historic building wall by combining modal identification method and optimal experiment design.
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Berger, Julien and Kadoch, Benjamin
- Subjects
THERMAL properties ,HISTORIC buildings ,THERMAL diffusivity ,EXPERIMENTAL design ,WALLS ,INVERSE problems ,HEAT transfer - Abstract
The estimation of wall thermal properties by in situ measurement enables to increase the reliability of the model predictions for building energy efficiency. Nevertheless, retrieving the unknown parameters has an important computational cost. Indeed, several computations of the heat transfer problem are required to identify these thermal properties. To handle this drawback, an innovative approach is investigated. The first step is to search the optimal experiment design among the sequence of observation of several months. A reduced sequence of observations of three days is identified which guarantees to estimate the parameter with the maximum accuracy. Moreover, the inverse problem is only solved for this short sequence. To decrease further the computational efforts, a reduced order model based on the modal identification method is employed. This a posteriori model reduction method approximates the solution with a lower degree of freedom. The whole methodology is illustrated to estimate the thermal diffusivity of an historical building that has been monitored with temperature sensors for several months. The computational efforts is cut by five. The estimated parameter improves the reliability of the predictions of the wall thermal efficiency. • Estimation of historical building wall thermal properties with by in situ measurement. • Innovative approach to reduce the computational effort to retrieve unknown parameters. • Reduced sequence of observations is defined using optimal experiment design approach. • A posteriori reduced order model based on the modal identification method is employed. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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35. Searching an optimal experiment observation sequence to estimate the thermal properties of a multilayer wall under real climate conditions.
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Jumabekova, Ainagul, Berger, Julien, Foucquier, Aurélie, and Dulikravich, George S.
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THERMAL properties , *PARAMETER estimation , *WALLS , *PHENOMENOLOGICAL theory (Physics) , *HISTORIC buildings , *CLIMATOLOGY , *CONSTRUCTION materials - Abstract
• D-optimum criterion is applied to select an optimal experiment duration. • Identifiability of parameters is demonstrated. • Thermal conductivity is estimated over the reduced measurement plan. • Parameter estimation problem is solved with hybrid optimization method. • Reliability of the model for one year experiment is achieved. The in situ estimation of the thermal properties of existing building wall materials is a computationally expensive procedure. Its cost is highly proportional to the duration of measurements. To decrease the computational cost a methodology using a D-optimum criterion to select an optimal experiment duration is proposed. This criterion allows to accurately estimate the thermal properties of the wall using a reduced measurement plan. The methodology is applied to estimate the thermal conductivity of the three-layer wall of a historical building in France. Three different experiment sequences (one, three and seven days) and three spatial distributions of the thermal conductivity are investigated. Then using the optimal duration of observations the thermal conductivity is estimated using the hybrid optimization method. Results show a significant reduction of computational time; and reliable simulation of physical phenomena using the estimated values. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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36. Critical assessment of a new mathematical model for hysteresis effects on heat and mass transfer in porous building material.
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Berger, Julien, Busser, Thomas, Colinart, Thibaut, and Dutykh, Denys
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CONSTRUCTION materials , *MASS transfer , *POROUS materials , *HEAT transfer , *MATHEMATICAL models , *HYSTERESIS - Abstract
The reliability of mathematical models for heat and mass transfer in building porous material is of capital importance. A reliable model permits to carry predictions of the physical phenomenon with sufficient confidence in the results. Among the physical phenomena, the hysteresis effects on moisture sorption and moisture capacity need to be integrated in the mathematical model of transfer. This article proposes to explore the use of an smooth Bang–Bang model to simulate the hysteresis effects coupled with heat and mass transfer in porous material. This model adds two supplementary differential equations to the two classical ones for heat and mass transfer. The solution of these equations ensures smooth transitions between the main sorption and desorption curves. Two parameters are required to control the speed of transition through the intermediary curves. After the mathematical description of the model, an efficient numerical model is proposed to compute the fields with accuracy and reduced computational efforts. It is based on the Du Fort–Frankel scheme for the heat and mass balance equations. For the hysteresis numerical model, an innovative implicit–explicit approach is proposed. Then, the predictions of the numerical model are compared with experimental observations from literature for two case studies. The first one corresponds to a slow cycle of adsorption and desorption while the second is based on a fast cycling case with alternative increase and decrease of moisture content. The comparisons highlight a very satisfactory agreement between the numerical predictions and the observations. In the last Section, the reliability and efficiency of the proposed model is investigated for long term simulation cases. The importance of considering hysteresis effects in the reliability of the predictions are enhanced by comparison with classical approaches from literature. • Building numerical model for heat and mass transfer with hysteresis effects. • Use of Bang–Bang model for modeling hysteresis on moisture sorption and capacity. • Comparison of the model reliability with two experimental benchmark from literature. • Saved computational effort and satisfactory agreement with experimental observations. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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37. Retraction notice to "On the estimation of moisture permeability and advection coefficients of a wood fibre material using the optimal experiment design approach" [Exp. Therm. Fluid Sci. 90 (2017) 246–259].
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Berger, Julien, Busser, Thomas, Dutykh, Denys, and Mendes, Nathan
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PERMEABILITY , *ADVECTION , *EXPERIMENTAL design , *MOISTURE , *FIBERS , *PRESSURE vessels - Published
- 2020
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38. Critical assessment of efficient numerical methods for a long-term simulation of heat and moisture transfer in porous materials.
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Abdykarim, Madina, Berger, Julien, Dutykh, Denys, Soudani, Lucile, and Agbossou, Amen
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POROUS materials , *HEAT transfer , *EULER method , *BUILDING performance , *PHENOMENOLOGICAL theory (Physics) - Abstract
The issue to predict the behavior of building materials during wide horizons of time is still challenging. Experimental set-ups, since they require to perform tests for several years, are costly, never at the full scale and inconvenient. Building Performance Simulation (BPS) programs are designed to perform predictions on computational machines and cut experimental costs significantly. Nonetheless, in the recent review of state–of–the–art, it was indicated that despite the wide range of programs, there are still some drawbacks in terms of the accuracy and the high computational cost. This paper investigates the application of an innovative numerical method, called Super–Time–Stepping (STS) method. It allows performing accurate simulations with time-steps much larger than with standard explicit approaches. These "super" time-steps also enable us to reduce the computational cost. In addition to that, the design of the method allows easier application for models in higher dimensions and with nonlinear parameters. The efficiency of the method is tested on linear and nonlinear academic cases. Further study for the reliability of the model is performed on an experimental case study. The experiment has been carried out on a rammed earth wall during almost 14 months. Obtained data is presented in this article and implemented into proposed model. As a result of the case studies, it is shown that in comparison to the euler explicit method, the STS methods can cut costs by more than five times while maintaining high accuracy and efficiency. A very fine analysis of the physical phenomena is also performed. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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39. Evaluation of the reliability of a heat and mass transfer model in hygroscopic material.
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Berger, Julien, Busser, Thomas, Reddy, Sohail, and Dulikravich, George S.
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MASS transfer coefficients , *MASS transfer , *HEAT transfer , *HEAT transfer coefficient , *POROUS materials , *PHENOMENOLOGICAL theory (Physics) - Abstract
• Reliability of model for heat and mass transfer in porous material is achieved. • An efficient numerical model is proposed to save computational efforts. • Inverse problem is solved to estimate uncertain input parameter. • Identifiability of the seven unknown coefficients is demonstrated. • Other experimental data are used to benchmark the numerical prediction of the model. The reliability of a model is its accuracy in predicting the physical phenomena. In this paper, the robustness of a model of heat and mass transfer in a porous material is evaluated by comparing the numerical predictions with experimental observations. An experimental facility composed of an enclosure made with spruce CLT panels is used. An increase of temperature is applied in the inside air volume to force the heat transfer from the inner to the outer surfaces. Sensors inside the material enables to have experimental observations of the physical phenomena. Before bench-marking the numerical model, a first set of experimental data is used to reduce the two major source of uncertainties in the model. Indeed, the first source arises from surface heat and mass transfer coefficients, usually determined by empirical correlations. The second comes the thermal conductivity of the material which is defined through standard methods as invariant for the three layers of the spruce panels. To overcome this issue, a set of seven uncertain parameters are estimated using an hybrid optimizer after demonstrating their theoretical and practical identifiability. Then, the reliability of the numerical model, based on the Du Fort–Frankel explicit scheme, is evaluated by comparison to a second set of experimental data obtained in another wall of the enclosure. A very satisfactory agreement is remarked showing the accuracy of the model to predict the physical phenomena in this hygroscopic porous material. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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40. Discovery of metamorphic microdiamonds from the parautochthonous units of the Variscan French Massif Central: Comment.
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Berger, Julien
- Published
- 2016
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41. Transition from subduction to collision recorded in the Pan-African arc complexes (Mali to Ghana).
- Author
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Guillot, Stéphane, Agbossoumondé, Yao, Bascou, Jérôme, Berger, Julien, Duclaux, Guillaume, Hilairet, Nadège, Ménot, René-Pierre, and Schwartz, Stéphane
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OROGENY , *COLLISIONS (Physics) , *CONTINENTAL margins , *GEOLOGICAL time scales , *CRATONS , *MAGMATISM - Abstract
Highlights • The suture zone of the Dahomeyide belt, exposed coronitic HP granulitic massifs. • The closure of Pharusian ocean occurred along intra-oceanic arc and active margin from 800 to 600 Ma. • Between 620 and 610 Ma, the forearc system and the tip of the active continental margin were buried synchronously. • The positive Bouguer anomaly East of the suture zone, could correspond to the underplated buried forearc. • The transition from continental subduction to continental collision occurred between 610 and 580 Ma. Abstract 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. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
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42. Magnetic fabric and flow direction in the Ediacaran Imider dyke swarms (Eastern Anti-Atlas, Morocco), inferred from the Anisotropy of Magnetic Susceptibility (AMS).
- Author
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Otmane, Khadija, Errami, Ezzoura, Olivier, Philippe, Berger, Julien, Triantafyllou, Antoine, and Ennih, Nasser
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STRUCTURAL geology , *MAGMATISM , *GEOLOGIC faults , *ANISOTROPY , *MAGNETIC susceptibility - Abstract
Located in the Imiter Inlier (Eastern Saghro, Anti-Atlas, Morocco), Ediacaran volcanic dykes have been studied for their petrofabric using Anisotropy of Magnetic Susceptibility (AMS) technique. Four dykes, namely TF, TD, FF and FE show andesitic compositions and are considered to belong to the same dyke swarm. They are oriented respectively N25E, N40E, N50E, and N10E and have been emplaced during a first tectonic event. The dyke FW, oriented N90E displays a composition of alkali basalt and its emplacement is attributed to a subsequent tectonic event. These rocks are propylitized under greenschist facies conditions forming a secondary paragenesis constituted by calcite, chlorite, epidote and sericite. The dykes TF, TD, FF and FE are sub-volcanic calc-alkaline, typical of post-collisional basalts/andesites, belonging to plate margin andesites. The FW dyke shows a within-plate basalt signature; alkaline affinity reflecting a different petrogenetic process. The thermomagnetic analyses show a dominantly ferromagnetic behaviour in the TF dyke core carried by single domain Ti-poor magnetite, maghemite and pyrrhotite. The dominantly paramagnetic susceptibilities in TF dyke rims and TD, FE, FF and FW dykes are controlled by ilmenite, amphibole, pyroxene and chlorite. The magnetic fabrics of the Imider dykes, determined by our AMS study, allows us to reconstitute the tectonic conditions which prevailed during the emplacement of these two generations of volcanic dykes. The first tectonic event was characterized by a roughly NE-SW compression and the second tectonic event is characterized by an E-W shortening followed by a relaxation recording the end of the Pan-African orogeny in the eastern Anti-Atlas. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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43. Petrology, geochemistry and Sm-Nd analyses on the Balkan-Carpathian Ophiolite (BCO – Romania, Serbia, Bulgaria): Remnants of a Devonian back-arc basin in the easternmost part of the Variscan domain.
- Author
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Plissart, Gaëlle, Monnier, Christophe, Diot, Hervé, Mărunţiu, Marcel, Berger, Julien, and Triantafyllou, Antoine
- Subjects
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PETROLOGY , *SAMARIUM isotopes , *NEODYMIUM isotopes , *GEOCHEMISTRY , *OPHIOLITES , *DEVONIAN Period - Abstract
The pre-Alpine basement of the Southern Carpathians/Western Balkans contains four ophiolitic massifs dismembered by Alpine tectonics, which define the “Balkan-Carpathian Ophiolite” (BCO) for which the tectonic setting and age of formation are still debated (Precambrian or Early Devonian). In this contribution, we demonstrate that, in light of a Pre-Alpine restoration, the four massifs belonged to a unique slice of very complete, obducted oceanic lithosphere and we re-evaluate its tectonic setting. Large chromitite volumes with Al-rich spinel compositions (Cr# = 0.39–0.48), as well as major and trace geochemical results on basalts (slightly enriched N-MORBs with low negative Nb anomaly associated with calk-alkaline BABBs), point to a formation in a back-arc basin. Mantle spinel composition (Cr# = 0.49–0.51) and melting modeling indicate mean melting extents of 8.5–11% favouring intermediate spreading rate. New Sm-Nd dating on lower gabbroic rocks give a whole rock isochron, interpreted as the age of formation of the BCO crust at 409 ± 38 Ma, thus confirming an Early Devonian oceanic crust. The previous ∼563 Ma U-Pb zircon age can be interpreted as casual inheritance indicating the proximity of an old continental lithosphere. Taking into account the lithological evidences and paleocontinental affinities of the two recognized terranes separated by the BC oceanic basin (Balkans and Sredna Gora) and by analogy with other Variscan ophiolites in Western/Central Europe, we suggest that the BC ophiolite belong to the ∼400 Ma ophiolites group obducted between West and East Galatia and belonging to the southern Variscan suture. However, the BC ophiolite is the only one of this group obducted to the north and not involved in the Lower Allochthon/ophiolite/Upper Allochthon thrust pile, likely explaining its exceptional preservation. Finally, we tentatively propose a new unifying tectonic model where different terrane drift rates and highly oblique displacements create two Rheic branches, the “Rheic” and the “Galicia-Brittany-Massif Central”. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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44. Comparison of uniform and piecewise-uniform heatings when estimating thermal properties of high-conductivity materials.
- Author
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D'Alessandro, Giampaolo, de Monte, Filippo, Gasparin, Suelen, and Berger, Julien
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THERMOPHYSICAL properties , *HEAT conduction , *THERMAL conductivity , *STANDARD deviations , *THERMAL properties , *HEAT flux , *MATERIALS testing - Abstract
• Uniform and partial heatings are compared when testing isotropic materials. • The plane source-based experimental apparatus is investigated. • A d -optimum criterion ensuring the convergence of the estimation procedure is used. • Experiment times, Δ+ determinant and uncertainty of the estimates are considered. • It is shown that the partial heating is not beneficial for isotropic materials. A d -optimum criterion is applied to the three-layer apparatus used for simultaneously estimating thermal properties (for example, thermal conductivity and effusivity) through the plane source method. The objective is to perform a comparison between uniform heating and piecewise-uniform heating of high-conductivity solid samples. In particular, the latter case is modeled through a two-dimensional heat conduction problem in which a rectangular plate (i.e. the sample) is partially heated at the front boundary through a surface heat flux, while all the other boundaries are kept insulated. The optimal experiment is designed for different set-ups of the experimental apparatus (width of the heated region, number of sensors and their locations). The convergence and the computational efficiency of the estimation iterative procedure are the terms of the comparison, as well as the expected standard deviations of thermal conductivity and effusivity. The results indicate that the use of a piecewise-uniform heating is not completely beneficial for isotropic materials. In fact, if on one hand it may offer standard deviations reduced up to about 40%, on the other hand it would require an experiment about six times longer than that required by a uniform heating to ensure a good convergence of the estimation iterative procedure. Therefore, a major computational effort is required. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
45. Relationship between a syntectonic granitic intrusion and a shear zone in the Southern Carpathian-Balkan area (Almăj Mountains, Romania): Implications for late Variscan kinematics and Cherbelezu granitoid emplacement
- Author
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Plissart, Gaëlle, Diot, Hervé, Monnier, Christophe, Mărunţiu, Marcel, and Berger, Julien
- Subjects
- *
CARBONIFEROUS Period , *GRANITE , *IGNEOUS intrusions , *SHEAR zones , *KINEMATICS - Abstract
Abstract: The Carboniferous Cherbelezu batholith (Almăj Mountains, Romania) is a well-preserved but poorly studied intrusion belonging to the Upper Danubian Alpine Nappe. This pluton crops out along a pre-existing major verticalized formation, the Corbu Mylonitic Zone (CMZ). Our study investigates the role of the CMZ on the deformation recorded during the mush emplacement and cooling. A detailed microstructural study of this granitic body, coupled with investigations on both Anisotropy of Magnetic Susceptibility (AMS) and Shape Preferred Orientation (SPO) of biotite subfabric, has been performed. The surrounding rocks preserve evidence that the CMZ has been reactivated as a sinistral strike-slip fault before the pluton emplacement. Microstructural investigations of the granitic facies indicate that the pluton has undergone superimposed deformations during its cooling, from submagmatic to LT conditions. Foliation and lineation patterns obtained by AMS and SPO – both methods giving similar results – reflect either magmatic/submagmatic or solid-state flows. Magmatic flow, preserved in the western and southern parts of the pluton, is characterized by concentric foliation pattern with both divergent and parallel lineations, the latter pointing to an early transcurrent regime. Subsequently, a solid-state deformation, recorded during the pluton cooling and restricted to its eastern and northern parts, argues for the concomitant CMZ activity under a sinistral transpressive regime. This is supported by the P′ and T parameter distributions, especially for SPO results, this technique showing clear advantages for the interpretation of the fabric scalar parameters. [Copyright &y& Elsevier]
- Published
- 2012
- Full Text
- View/download PDF
46. Nephrectomy improves overall survival in patients with metastatic renal cell carcinoma in cases of favorable MSKCC or ECOG prognostic features.
- Author
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Mathieu, Romain, Pignot, Géraldine, Ingles, Alexandre, Crepel, Maxime, Bigot, Pierre, Bernhard, Jean-Christophe, Joly, Florence, Guy, Laurent, Ravaud, Alain, Azzouzi, Abdel Rahmene, Gravis, Gwenaelle, Chevreau, Christine, Zini, Laurent, Lang, Hervé, Pfister, Christian, Lechevallier, Eric, Fais, Pierre-Olivier, Berger, Julien, Vayleux, Bertrand, and Roupret, Morgan
- Subjects
- *
RENAL cancer patients , *RENAL cancer treatment , *NEPHRECTOMY , *TARGETED drug delivery , *HEALTH outcome assessment - Abstract
Objectives The role of cytoreductive nephrectomy (CN) in the treatment of patients harboring metastatic renal cell carcinoma (mRCC) has become controversial since the emergence of effective targeted therapies. The aim of our study was to compare the overall survival (OS) between CN and non-CN groups of patients presenting with mRCC in the era of targeted drugs and to assess these outcomes among the different Memorial Sloan-Kettering Cancer Center (MSKCC) and The Eastern Cooperative Oncology Group (ECOG) performance status subgroups. Methods and materials A total of 351 patients with mRCC at diagnosis recruited from 18 tertiary care centers who had been treated with systemic treatment were included in this retrospective study. OS was assessed by the Kaplan-Meier method according to the completion of a CN. The population was subsequently stratified according to MSKCC and ECOG prognostic groups. Results Median OS in the entire cohort was 37.1 months. Median OS was significantly improved for patients who underwent CN (16.4 vs. 38.1 months, P <0.001). However, subgroup analysis demonstrated that OS improvement after CN was only significant among the patients with an ECOG score of 0 to 1 (16.7 vs. 43.3 months, P = 0.03) and the group of patients with good and intermediate MSKCC score (16.8 vs. 42.4 months, P = 0.02). On the contrary, this benefit was not significant for the patients with an ECOG score of 2 to 3 (8.0 vs. 12.6 months, P = 0.8) or the group with poor MSKCC score (5.2 vs. 5.2, P = 0.9). Conclusions CN improves OS in patients with mRCC. However, this effect does not seem to be significant for the patients in ECOG performance status groups of 2 to 3 or poor MSKCC prognostic group. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
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