Modeling Group

@article{amirat_2247,

title = {Homogenization of ferrofluid flow models in porous media with Langevin magnetization law},

author = {Youcef Amirat and Kamel Hamdache},

url = {https://www.sciencedirect.com/science/article/pii/S0022247X23001324?via%3Dihub},

year  = {2023},

date = {2023-09-01},

journal = {Journal Of Mathematical Analysis And Applications},

volume = {525},

number = {1},

pages = {127129},

abstract = {The paper is concerned with the homogenization of the equations describing the flow of a ferrofluid through a heterogeneous porous medium ? in the presence of an applied magnetic field. We discuss two models where the magnetization M is parallel to the magnetic field H. In the first one M and H satisfy the relation M=?01?fH in ?, where ?0 is a positive constant and 1?f is the characteristic function of ?f (the pore space). In the second model, M and H satisfy the Langevin magnetization law M=MsL(b1|H|)|H|1?fH, where L is the Langevin function given by L(x)=1tanh?x?1x, Ms is the saturation magnetization and b1 is a positive physical constant. The velocity and the pressure satisfy the Stokes equation with a Kelvin magnetic force. We perform the homogenization of the equations of each of the two models. Using the two-scale convergence method, we rigorously derive the homogenized equation for the magnetic potential and determine the asymptotic limit of the magnetization. Then we rigorously derive a Darcy law.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{fortin_2076,

title = {A very high order discontinuous Galerkin method for the numerical solution of stiff DDEs},

author = {André Fortin and Driss Yakoubi},

url = {https://www.sciencedirect.com/science/article/pii/S0096300322008359},

year  = {2023},

date = {2023-04-01},

journal = {Applied Mathematics And Computation},

volume = {443},

pages = {127767},

abstract = {We present a high order discontinuous Galerkin (DG) method for the numerical solution of systems of delay differential equations (DDEs). The method is based on Legendre orthogonal polynomials of high degree k (typically k=10) in each subinterval and is a generalisation to DDEs of a similar method which proved to be very efficient for ordinary differential equations (ODEs). We show how the error can be estimated allowing to control the size of the time step. We also propose a particularly efficient quasi Newton method for the solution of the resulting non linear systems based on a very accurate approximation of the Jacobian matrix that is very easy to implement and with excellent convergence properties. The method is then applied to very stiff systems of DDEs.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{yakoubi_2302,

title = {Enhancing the viscosity-splitting method to solve the time-dependent Navier-Stokes equations},

author = {Driss Yakoubi},

url = {https://www.sciencedirect.com/science/article/abs/pii/S100757042300182X},

year  = {2023},

date = {2023-04-01},

journal = {Communications In Nonlinear Science And Numerical Simulation},

volume = {123},

number = {2023},

pages = {107264},

abstract = {The viscosity-splitting (VS) scheme for solving the incompressible time-dependent Navier-Stokes equations consists to decouple the full problem into two easy subproblems to resolve.

This method splits the nonlinearity (convection term) and the incompressibility into two different steps. As a result, every subproblem is easier to solve than the Navier-Stokes system. The semi-implicit approach is mostly used in the first step for the nonlinearity term and the intermediate velocity is calculated by dropping the pressure gradient. We then resolve a linear Stokes problem in the next step.

We present a modified viscosity-splitting scheme (Incremental viscosity-splitting) (IVS) to improve this method. This scheme adds the gradient of the pressure (calculated at the previous time step) in the first step and modifies the Stokes equations in the second step to

predict a better value of the intermediate velocity. A manufactured solution and two well-known benchmarks will be used to demonstrate the effectiveness of the suggested strategy.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{samah_2080,

title = {Review on ice crystallization and adhesion to optimize ice slurry generators without moving components},

author = {Walid Samah and Pascal Clain and François Rioual and Laurence Fournaison and Anthony Delahaye},

url = {https://www-sciencedirect-com.devinci.idm.oclc.org/science/article/pii/S1359431123000030},

year  = {2023},

date = {2023-03-01},

journal = {Applied Thermal Engineering},

volume = {223},

pages = {119974},

abstract = {The current climate crisis requires a radical reduction in energy consumption and greenhouse gas emissions. For the refrigeration industry, secondary refrigeration is one of the most accessible solutions to reduce the use of refrigerants with high greenhouse gas content. In addition, the use of low environmental impact two-phase secondary fluids, namely PCM (phase change material) slurries, such as ice slurries and gas hydrate slurries, can limit the electrical energy consumption involved in the process. Currently, the industry's most commonly used ice slurry production systems are scraped surface and supercooling generators. These have some disadvantages, such as maintenance costs and energy consumption. An ice slurry generator is considered efficient if it meets three criteria: continuous production, low energy consumption and reliable operation. Optimizing ice slurry production with generators without moving components (scraped surface) could be a solution to meet these criteria. The objective of this review is to present a critical analysis of ice slurry production optimization methods proposed in the literature. These methods aim either to prevent ice nucleation to produce supercooled water with a high supercooling degree, or to reduce the adhesion of the ice to the generator walls to facilitate its removal by flow or by external forces (gravity and buoyancy).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{venkateswaran_2256,

title = {Mapping the Tilt & Torsion angles for a 3-SPS-U parallel mechanism},

author = {Swaminath Venkateswaran and Damien Charles Chablat},

url = {https://www.mdpi.com/2218-6581/12/2/50},

year  = {2023},

date = {2023-03-01},

journal = {Robotics},

volume = {12},

number = {2},

pages = {1-19},

abstract = {This article presents the analysis of a parallel mechanism of type 3-SPS-U. The usual singularity approach is carried out with respect to the Euler angles of the universal joint. However, this approach is computationally expensive especially when stacked structures are analyzed. Thus, the positioning of the mobile platform for the mechanism is analyzed using the theory of Tilt & Torsion (T&T). The singularity-free workspace and the tilt limits of the mechanism are disclosed through this method. These workspaces can then be mapped to the Euler angles of the universal joint and the relation between the T & T space and the Euler space is demonstrated and validated in this study. Initially, simulations are performed using the results of singularity analysis to have a comparison between the T&T space and the Euler space. Experimental validation is then carried out on the prototype of the mechanism to perform a circular trajectory, in line with the simulations. The outcome of this study will be helpful for the integration of the mechanism for a piping inspection robot and also for the analysis of stacked architectures.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{fortin_2280,

title = {High accuracy breaking point detection for stiff DDEs},

author = {André Fortin and Driss Yakoubi},

url = {https://www.sciencedirect.com/science/article/abs/pii/S0893965923000976#d1e179},

year  = {2023},

date = {2023-03-01},

journal = {Applied Mathematics Letters},

volume = {143},

number = {2023},

pages = {Paper No. 108665},

abstract = {We have recently introduced a very high order Discontinuous Galerkin (DG) method for the solution of stiff ordinary differential equations (ODEs) and delay differential equations (DDEs). In this communication we focus on the detection of breaking points frequently arising in the solution of stiff DDEs. Breaking points are discontinuities appearing in the solution of DDEs and/or in some of its derivatives. Breaking points affect the efficiency of the numerical method by forcing very small time steps in their vicinity. They also locally affect the solution accuracy. We therefore introduce a very simple breaking point detection algorithm in order to further improve the efficiency our DG method.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{salehy_2291,

title = {Rheological properties of CO2 hydrate slurries in presence of Dioctyl sodium sulfosuccinate (AOT) in a dynamic loop for refrigeration application},

author = {Yasmine Salehy and Pascal Clain and Amokrane Boufares and Nada Chami and Jean-Philippe Torré and Didier Dalmazzone and Laurence Fournaison and Anthony Delahaye},

url = {https://www.sciencedirect.com/science/article/pii/S0009250923002725?via%3Dihub},

year  = {2023},

date = {2023-03-01},

journal = {Chemical Engineering Science},

volume = {275},

pages = {118716},

abstract = {Recent studies have shown real potential for using hydrate slurries as a secondary fluid in indirect refrigeration systems. However, pipeline clogging problems can appear due to hydrate agglomeration. Additives are generally used to counteract these problems. In this study, rheological properties of CO2 hydrate slurries in the presence of an additive Dioctyl sodium sulfosuccinate (AOT) are investigated. The capillary viscometer method is used to determine the fluid behaviour and the AOT impact on the slurry rheology. A dynamic loop is set up to collect experimental pressure drop and volume flow rate data. Based on the Rabinowitch and Mooney approach and Herschel-Bulkley model to determine the rheological properties, a shear-thinning behaviour was observed. The importance of the behaviour index choice in the procedure is discussed. Finally, the results obtained with AOT are compared with pre-existing studies. The present study highlights the AOT potential to significantly improve the CO2 hydrate slurries properties.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{hamdache_2246,

title = {The Bloch-Torrey limit of a kinetic transport system},

author = {Kamel Hamdache and Djamila Hamroun},

url = {https://link.springer.com/article/10.1007/s00009-023-02328-y#citeas},

year  = {2023},

date = {2023-02-01},

journal = {Mediterranean Journal Of Mathematics},

abstract = {This work is devoted to highlighting the diffusion of some models of Kinetic-Bloch system by an asymptotic analysis. The limit of the kinetic equation when using the classical diffusion scaling shows that the magnetization field becomes parallel to the magnetic field. For the limit of the magnetization when we use a second scaling of the kinetic equation, we show that the dynamics of the magnetization is driven by the Bloch-Torrey diffusion equation.},

keywords = {},

pubstate = {online},

tppubtype = {article}

}

@article{borsoni_1875,

title = {Compactness property of the linearized Boltzmann operator for a polyatomic gas undergoing resonant collisions},

author = {Thomas Borsoni and Laurent Boudin and Francesco Salvarani},

url = {https://www.sciencedirect.com/science/article/pii/S0022247X22005935?via%3Dihub},

year  = {2023},

date = {2023-01-01},

journal = {Journal Of Mathematical Analysis And Applications},

volume = {517},

number = {1},

pages = {126579},

abstract = {In this paper, we investigate a compactness property of the linearized Boltzmann operator in the context of a polyatomic gas whose molecules undergo resonant collisions. The peculiar structure of resonant collision rules allows to tensorize the problem into a velocity-related one, neighbouring the monatomic case, and an internal energy-related one. Our analysis is based on a specific treatment of the internal energy contributions. We also propose a geometric variant of Grad's proof of the same compactness property in the monatomic case.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{chami_1961,

title = {Rheological study of mixed cyclopentane + CO2 hydrate slurry in a dynamic loop for refrigeration systems},

author = {Nada Chami and Yasmine Salehy and Dennis Burgner and Pascal Clain and Didier Dalmazzone and Anthony Delahaye and Laurence Fournaison},

url = {https://www.sciencedirect.com/science/article/pii/S0360544222025476},

year  = {2023},

date = {2023-01-01},

journal = {Energy},

volume = {263},

pages = {125661},

abstract = {The use of CO2 hydrates as phase change materials is promising for secondary loop refrigeration, as these compounds present adjustable dissociation temperature that can be higher than 273.15 K and have high enthalpy of dissociation. In the present work, by using various promoters, cyclopentane (CP) in this study, the formation pressure of hydrates may be significantly lowered than CO2 hydrates. For their application as a secondary refrigerant, the rheological properties of mixed CP + CO2 hydrate slurry need to be controlled. The flow properties of CP and mixed CP + CO2 hydrate slurries were studied in a dynamic flow loop at different cyclopentane contents ranging from 3 wt% to 15 wt%, using a capillary viscometer based on Rabinowitch and Mooney equation. Rheological parameters (viscosity, flow behavior...) related to these two slurries were compared. The experimental results demonstrate that CP and mixed CP + CO2 hydrates slurries exhibit a shear thinning behavior and the viscosity values vary between 3 and 12 mPa.s-1 at [100-1000 s?1] for CP hydrates slurries and between 2 and 10 mPa s?1 at [100-1200 s?1] for CP + CO2 hydrates slurries. CP hydrate and CP + CO2 hydrate slurry viscosity is close to that of TBPB hydrate and lower than that of CO2 hydrate. Moreover, mixed CP + CO2 have shown a time-evolution of the rheological behavior.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{samah_2025,

title = {Experimental investigation on the wetting behavior of a superhydrophobic surface under controlled temperature and humidity},

author = {Walid Samah and Pascal Clain and François Rioual and Laurence Fournaison and Anthony Delahaye},

url = {https://www.sciencedirect.com/science/article/pii/S0927775722022063},

year  = {2023},

date = {2023-01-01},

volume = {656},

pages = {130451},

abstract = {Superhydrophobic surfaces (SHS) are of great interest in various industrial fields. However, the application of these surfaces in cold, humid and submerged environments (as in the case of ice slurry production) sometimes presents problems related to the loss of their superhydrophobic properties. This paper presents an experimental study in order to characterize the wetting behavior of a surface coated with a commercial superhydrophobic "Ultra Ever Dry" (UED) coating at different surface temperatures (from 22 °C to ? 13 °C) and relative humidity (13%, 20%, 30%, 40% and 50%). Three methods are developed to characterize the wetting behavior. The first method consists in depositing a water drop on the cooled superhydrophobic UED surface. The objective is to characterize the static wetting behavior (evolution of contact angles) during the cooling of the surface for different relative humidity. The second method consists in dropping a water drop on the cooled UED superhydrophobic surface with an impact velocity of 1 m s?1. This method allows the dynamic behavior of the wetting (impact and rebound of the drop) to be characterized at different temperatures. The third method, consists in studying the effect of the immersion of the SHS in a volume of water cooled until supercooling then freezing. The aim is to analyze the wetting behavior in immersion at low temperature. The results of the static wetting study show that the superhydrophobic coating loses its non-wetting properties at temperatures below 13 °C for a relative humidity between 13% and 50% due to condensation on the surface. The results of the dynamic wetting study show that the superhydrophobic coating has poor resistance to water drop impact at surface temperatures below 4 °C. The wetting transition from Cassie to Wenzel state in low temperature immersion is caused by ice formation. The wettability state influences the morphology of the ice produced after freezing.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vanaei_2061,

title = {Numerical-Experimental Analysis toward the Strain Rate Sensitivity of 3D-Printed Nylon Reinforced by Short Carbon Fiber},

author = {Hamidreza Vanaei and Anouar El Magri and Mohammadali Rastak and Saeedeh Vanaei and Sébastien Vaudreuil and Abbas Tcharkhtchi},

url = {https://doi.org/10.3390/ma15248722},

year  = {2022},

date = {2022-12-01},

journal = {Materials},

volume = {15},

number = {24},

pages = {8722},

abstract = {Despite the application of the Additive Manufacturing process and the ability of parts' construction directly from a 3D model, particular attention should be taken into account to improve their mechanical characteristics. In this paper, we present the effect of individual process variables and the strain-rate sensitivity of Onyx (Nylon mixed with chopped carbon fiber) manufactured by Fused Filament Fabrication (FFF), using both experimental and simulation manners. The main objective of this paper is to present the effect of the selected printing parameters (print speed and platform temperature) and the sensitivity of the 3D-printed specimen to the strain rate during tensile behavior. A strong variation of tensile behavior for each set of conditions has been observed during the quasi-static tensile test. The variation of 40 °C in the platform temperature results in a 10% and 11% increase in Young's modulus and tensile strength, and 8% decrease in the failure strain, respectively. The variation of 20 mm·s?1 in print speed results in a 14% increase in the tensile strength and 11% decrease in the failure strain. The individual effect of process variables is inevitable and affects the mechanical behavior of the 3D-printed composite, as observed from the SEM micrographs (ductile to brittle fracture). The best condition according to their tensile behavior was chosen to investigate the strain rate sensitivity of the printed specimens both experimentally and using Finite Element (FE) simulations. As observed, the strain rate clearly affects the failure mechanism and the predicted behavior using the FE simulation. Increase in the elongation speed from 1 mm·min?1 to 100 mm·min?1, results in a considerable increase in Young's modulus. SEM micrographs demonstrated that although the mechanical behavior of the material varied by increasing the strain rate, the failure mechanism altered from ductile to brittle failure.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vaudreuil_2062,

title = {Effects of Power and Laser Speed on the Mechanical Properties of AlSi7Mg0.6 Manufactured by Laser Powder Bed Fusion},

author = {Sébastien Vaudreuil and Salah Eddine Bencaid and Hamidreza Vanaei and Anouar El Magri},

url = {https://doi.org/10.3390/ma15238640},

year  = {2022},

date = {2022-12-01},

journal = {Materials},

volume = {15},

number = {23},

pages = {8640},

abstract = {The AlSi7Mg0.6 alloy, with its good tolerance against strain, is used in laser powder bed fusion (LPBF) to produce parts with complex geometries for aerospace engineering. Production of parts with good mechanical strength requires, however, the optimization of laser parameters. This study thus evaluated the influence of scanning speed, laser power, and strategy on several mechanical properties (tensile/resilience/hardness) to identify an optimal processing region. Results have shown the profound influence of laser power and scanning speed on mechanical properties, with a limited influence from the laser strategy. Tensile strength values ranging from 122 to 394 MPa were obtained, while Young's Modulus varied from 17 to 29 GPa, and the elongation at break ranged from 2.1 to 9.8%. Surface plots of each property against laser power and speed revealed a region of higher mechanical properties. This region is found when using 50 µm thick layers for energy densities between 25 and 35 J/mm3. Operating at higher values of energy density yielded sub-optimal properties, while a lower energy density resulted in poor performances. Results have shown that any optimization strategy must not only account for the volumic energy density value, but also for laser power itself when thick layers are used for fabrication. This was shown through parts exhibiting reduced mechanical performances that were produced within the optimal energy density range, but at low laser power. By combining mid-speed and power within the optimal region, parts with good microstructure and limited defects such as balling, keyhole pores, and hot cracking will be produced. Heat-treating AlSi7Mg0.6 parts to T6 temper negatively affected mechanical performances. Adapted tempering conditions are thus required if improvements are sought through tempering.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{bottino_2298,

title = {Time evolution and finite element representation of Phase Space Zonal Structures in ORB5},

author = {Alberto Bottino and Matteo Valerio Falessi and Thomas Hayward-Schneider and Alessandro Biancalani and Sergio Briguglio and R Hatzky and Philipp Lauber and Alexey Mishchenko and Emanuele Poli and B Rettino and Francesco Vannini and Xin Wang and Fulvio Zonca},

url = {https://dx.doi.org/10.1088/1742-6596/2397/1/012019},

year  = {2022},

date = {2022-12-01},

journal = {Journal of Physics: Conference Series},

volume = {2397},

pages = {012019},

abstract = {Phase Space Zonal Structures (PSZSs), obtained by averaging out dependencies on angle-like variables in the energetic particle (EP) distribution function, play a fundamental role in regulating EP transport induced by Alfvén instabilities in burning plasmas, acting as a slowly varying nonlinear equilibrium state. Therefore, they are of great interest for the development of reduced models for the description of EP heat and particle transport on long time scales, comparable with the energy confinement time, for future burning plasma experiments. In this work, we propose an efficient finite element based projection of the time evolution of the PSZS, suited for global particle-in-cell (PIC) gyrokinetic (GK) codes. The resulting algorithm has been implemented in the global GK PIC code ORB5. PSZSs can not only be used for validating reduced models, but also as a diagnostic tool for characterizing the nonlinear interaction in phase space between Alfvén instabilities and EPs in global GK simulations.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vannini_2300,

title = {Gyrokinetic modelling of the Alfvén mode and EGAM activity in ASDEX Upgrade},

author = {Francesco Vannini and Alessandro Biancalani and Alberto Bottino and Thomas Hayward-Schneider and Philipp Lauber and Alexey Mishchenko and Emanuele Poli and B Rettino and Gregorio Vlad and Xin Wang and ASPEX Upgrade Team},

url = {https://dx.doi.org/10.1088/1742-6596/2397/1/012003},

year  = {2022},

date = {2022-12-01},

journal = {Journal of Physics: Conference Series},

volume = {2397},

number = {1},

pages = {012003},

abstract = {Energetic particles present in tokamak machines can drive through resonant wave-particle interaction different plasma instabilities, e.g Alfvén modes and energetic particle-driven geodesic acoustic modes (EGAMs). While the former are potentially detrimental as they can enhance the energetic particle transport and damage the machine wall, the latter are axisymmetric, possibly benign modes that can act to regulate turbulence. A unique scenario, the so-called NLED-AUG case, has been developed in ASDEX Upgrade by tuning the plasma parameters so that the energetic particle kinetic energy is 100 times higher than that of the background plasma, like in ITER. An intense energetic particle-driven activity is observed, most prominently various Alfvén mode bursts triggering chirping EGAMs. The present work reports studies on the Alfvén mode and EGAM dynamics showing, for the first time, many toroidal mode gyrokinetic simulations with ORB5 where the NLED-AUG case scenario is considered. We study the mode dynamics modelling the energetic particles with different equilibrium distribution functions, such as: isotropic slowing-down, double-bump-on-tail and equivalent Maxwellian. We retain, at the beginning, the nonlinearities only in the energetic particle dynamics. Later, also the background plasma species nonlinearities are taken into account.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ouassil_2046,

title = {Investigating the effect of printing conditions and annealing on the porosity and tensile behavior of 3D-printed polyetherimide material in Z-direction},

author = {Salah-Eddine Ouassil Ouassil and Anouar El Magri and Hamidreza Vanaei and Sébastien Vaudreuil},

url = {https://doi.org/10.1002/app.53353},

year  = {2022},

date = {2022-11-01},

journal = {Journal Of Applied Polymer Science},

volume = {Not assigned yet},

number = {e53353},

pages = {53353},

abstract = {Fused filament fabrication process presents drawbacks in mechanical properties observed when printing in the build direction (Z-direction). Such anisotropic properties will affect the part's performances and have to be minimized during fabrication. This study aims to evaluate the effects of nozzle temperature, printing speed and specimen state (annealed or as-printed) on porosity percentage and tensile properties for 3D printed polyetherimide (PEI) (ULTEM 1010) parts in Z-direction. The results demonstrated that print speed is the most influential process parameter that should be adjusted in consideration with the other printing parameters. The specimens' state did not reveal a noticeable influence, as the amorphous nature of PEI is considered less receptive to annealing. The optimization method to achieve the best results yielded values of 360 °C and 30 mm/s as printing conditions, followed by heat treatment. This was confirmed by porosity measurements, tensile testing, and scanning electron microscopy observations. The best performances of PEI material were 3425.5 MPa, 102 MPa, and 4.30% for Young's modulus, tensile strength, and elongation at break, respectively.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vannini_2299,

title = {Gyrokinetic modelling of the Alfvén mode activity in ASDEX Upgrade with an isotropic slowing-down fast-particle distribution},

author = {Francesco Vannini and Alessandro Biancalani and Alberto Bottino and Thomas Hayward-Schneider and Philipp Lauber and Alexey Mishchenko and Emanuele Poli and B Rettino and Gregorio Vlad and Xin Wang and ASPEX Upgrade Team},

url = {https://dx.doi.org/10.1088/1741-4326/ac8b1e},

year  = {2022},

date = {2022-11-01},

journal = {Nuclear Fusion},

volume = {62},

number = {12},

pages = {126042},

abstract = {In the present paper, the evolution of the Alfvén modes (AMs) is studied in a realistic ASDEX Upgrade equilibrium by analyzing the results of simulations with the global, electromagnetic, gyrokinetic particle-in-cell code ORB5. The energetic particles (EPs) are modelled both via the newly implemented isotropic slowing-down and with Maxwellian distribution functions. The comparison of the numerical results shows that modelling the EPs with the equivalent Maxwellian rather than with the slowing-down, does not significantly affect the frequency of the driven AM, while its growth rate appears to be underestimated with a quantitative difference as large as almost 30%. Additionally the choice of the isotropic slowing-down allows a better description of the nonlinear modification of the dominant AM frequency, while an equivalent Maxwellian underestimates it. A good comparison with the experimental spectrogram is found.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{benmesbah_1960,

title = {Calorimetric study of carbon dioxide (CO2) hydrate formation and dissociation processes in porous media},

author = {Fatima Benmesbah and Pascal Clain and Olivia Fandino and Véronique Osswald and Laurence Fournaison and Christophe Dicharry and Anthony Delahaye},

url = {https://www.sciencedirect.com/science/article/pii/S0009250922006923},

year  = {2022},

date = {2022-10-01},

journal = {Chemical Engineering Science},

volume = {264},

pages = {118108},

abstract = {Understanding the formation and dissociation mechanisms of gas hydrate in porous media is important for the development of new energy-efficient and environmentally friendly technologies related to cold storage as they provide significant latent heat and energy density at suitable phase change temperature. The challenge is to understand the interactions between gas hydrates and the chosen storage media in order to assess the operating conditions likely to optimize time and energy consumption in cold production and storage systems. In this work, CO2 hydrates formation and dissociation are investigated in two morphologically different porous materials: sand and silica gels. A calorimetric approach is applied to study both the CO2 hydrate formation kinetics, particularly the induction time, and the amount of hydrate formed for each of the two porous materials. The experiments are performed using a differential thermal analysis device with two identical measuring cells. The present work is focused on assessing the effect of key factors like water saturation, particle size and the morphology of porous media on CO2 hydrate formation and dissociation processes. Overall, the results do not show a statistically significant correlation between these factors and the induction time. Interestingly, the results obtained with dual porous silica gel showed a higher amount of hydrate formed compared to those with sand for similar initial pressure, temperature and water content conditions. This result may be due to the fact that silica gels provide higher surface area due to their smaller particle size (20-45 µm vs 80-450 µm for sand), and the presence of internal pore volume in silica gel particles.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{vanaei_1962,

title = {Roadmap: Numerical-Experimental Investigation and Optimization of 3D-Printed Parts Using Response Surface Methodology},

author = {Hamidreza Vanaei and Sofiane Khelladi and Abbas Tcharkhtchi},

url = {https://www.mdpi.com/1996-1944/15/20/7193},

year  = {2022},

date = {2022-10-01},

journal = {Materials},

volume = {15},

number = {20},

pages = {7193},

abstract = {Several process variables can be taken into account to optimize the fused filament fabrication (FFF) process, a promising additive manufacturing technique. To take into account the most important variables, a numerical-experimental roadmap toward the optimization of the FFF process, by taking into account some physico-chemical and mechanical characteristics, has been proposed to implement the findings through the thermal behavior of materials. A response surface methodology (RSM) was used to consider the effect of liquefier temperature, platform temperature, and print speed. RSM gave a confidence domain with a high degree of crystallinity, Young's modulus, maximum tensile stress, and elongation at break. Applying the corresponding data from the extracted zone of optimization to the previously developed code showed that the interaction of parameters plays a vital role in the rheological characteristics, such as temperature profile of filaments during deposition. Favorable adhesion could be achieved through the deposited layers in the FFF process. The obtained findings nurture motivations for working on the challenges and bring us one step closer to the optimization objectives in the FFF process to solve the industrial challenges.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{el_magri_1958,

title = {Effects of Laser Power and Hatch Orientation on Final Properties of PA12 Parts Produced by Selective Laser Sintering},

author = {Anouar El Magri and Hamidreza Vanaei and Salah Eddine Bencaid and Sébastien Vaudreuil},

url = {https://doi.org/10.3390/polym14173674},

year  = {2022},

date = {2022-09-01},

journal = {Polymers},

volume = {14},

number = {17},

pages = {3674},

abstract = {Poly(dodecano-12-lactam) (commercially known as polyamide ?PA12?) is one of the most resourceful materials used in the selective laser sintering (SLS) process due to its chemical and physical properties. The present work examined the influence of two SLS parameters, namely, laser power and hatch orientation, on the tensile, structural, thermal, and morphological properties of the fabricated PA12 parts. The main objective was to evaluate the suitable laser power and hatching orientation with respect to obtaining better final properties. PA12 powders and SLS-printed parts were assessed through their particle size distributions, X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), a scanning electron microscope (SEM), and their tensile properties. The results showed that the significant impact of the laser power while hatching is almost unnoticeable when using a high laser power. A more significant condition of the mechanical properties is the uniformity of the powder bed temperature. Optimum factor levels were achieved at 95% laser power and parallel/perpendicular hatching. Parts produced with the optimized SLS parameters were then subjected to an annealing treatment to induce a relaxation of the residual stress and to enhance the crystallinity. The results showed that annealing the SLS parts at 170 °C for 6 h significantly improved the thermal, structural, and tensile properties of 3D-printed PA12 parts.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{el_magri_1892,

title = {Effects of Laser Power and Hatch Orientation on Final Properties of PA12 Parts Produced by Selective Laser Sintering},

author = {Anouar El Magri and Salah Eddine Bencaid and Hamidreza Vanaei and Sébastien Vaudreuil},

url = {https://www.mdpi.com/2073-4360/14/17/3674},

year  = {2022},

date = {2022-09-01},

journal = {Polymers},

volume = {14},

number = {17},

pages = {3674},

abstract = {Poly(dodecano-12-lactam) (commercially known as polyamide ?PA12?) is one of the most resourceful materials used in the selective laser sintering (SLS) process due to its chemical and physical properties. The present work examined the influence of two SLS parameters, namely, laser power and hatch orientation, on the tensile, structural, thermal, and morphological properties of the fabricated PA12 parts. The main objective was to evaluate the suitable laser power and hatching orientation with respect to obtaining better final properties. PA12 powders and SLS-printed parts were assessed through their particle size distributions, X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), a scanning electron microscope (SEM), and their tensile properties. The results showed that the significant impact of the laser power while hatching is almost unnoticeable when using a high laser power. A more significant condition of the mechanical properties is the uniformity of the powder bed temperature. Optimum factor levels were achieved at 95% laser power and parallel/perpendicular hatching. Parts produced with the optimized SLS parameters were then subjected to an annealing treatment to induce a relaxation of the residual stress and to enhance the crystallinity. The results showed that annealing the SLS parts at 170 °C for 6 h significantly improved the thermal, structural, and tensile properties of 3D-printed PA12 parts},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{boudin_1894,

title = {A kinetic model of polyatomic gas with resonant collisions},

author = {Laurent Boudin and Alex Rossi and Francesco Salvarani},

url = {https://doi.org/10.1007/s11587-022-00733-1},

year  = {2022},

date = {2022-09-01},

journal = {Ricerche Di Matematica},

keywords = {},

pubstate = {online},

tppubtype = {article}

}

@article{bader_1995,

title = {Microscopic tridomain model of electrical activity in the heart with dynamical gap junctions. Part 2 - Derivation of the macroscopic tridomain model by unfolding homogenization method},

author = {Fakhrielddine Bader and Mostafa Bendahmane and Mazen Saad and Raafat Talhouk},

url = {https://doi.org/10.3233/ASY-221804},

year  = {2022},

date = {2022-09-01},

journal = {Asymptotic Analysis},

abstract = {We study the homogenization of a novel microscopic tridomain system, allowing

for a more detailed analysis of the properties of cardiac conduction than the classical bidomain

and monodomain models. In [5], we detail this model in which gap junctions are considered

as the connections between adjacent cells in cardiac muscle and could serve as alternative

or supporting pathways for cell-to-cell electrical signal propagation. Departing from this mi-

croscopic cellular model, we apply the periodic unfolding method to derive the macroscopic

tridomain model. Several diculties prevent the application of unfolding homogenization

results, including the degenerate temporal structure of the tridomain equations and a nonlin-

ear dynamic boundary condition on the cellular membrane. To prove the convergence of the

nonlinear terms, especially those dened on the microscopic interface, we use the boundary

unfolding operator and a Kolmogorov-Riesz compactness's result.},

keywords = {},

pubstate = {online},

tppubtype = {article}

}

@article{mishchenko_2296,

title = {Gyrokinetic particle-in-cell simulations of electromagnetic turbulence in the presence of fast particles and global modes},

author = {Alexey Mishchenko and Alberto Bottino and Thomas Hayward-Schneider and Emanuele Poli and Xin Wang and C Nührenberg and Alessandro Biancalani and E Lanti and Philipp Lauber and R Hatzky and Francesco Vannini and Laurent Villard and F Widmer},

url = {https://dx.doi.org/10.1088/1361-6587/ac8dbc},

year  = {2022},

date = {2022-09-01},

journal = {Plasma Physics And Controlled Fusion},

volume = {64},

number = {10},

pages = {104009},

abstract = {Global simulations of electromagnetic turbulence in circular-flux-surface tokamak and ASDEX-Upgrade geometry, tearing instabilities and their combination with the electromagnetic turbulence, nonlinear Alfvénic modes in the presence of fast particles and their combination with the electromagnetic turbulence and global electromagnetic turbulence in Wendelstein 7-X stellarator geometry are carried out using the gyrokinetic particle-in-cell code ORB5 (Lanti et al 2020 Comp. Phys. Comm. 251 107072) and EUTERPE (Kornilov et al 2004 Phys. Plasmas 11 3196). Computational feasibility of simulating such complex coupled systems is demonstrated. For simplicity, the reduced mass ratio is used throughout the paper.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{salhi_1885,

title = {Well-posedness and numerical approximation of steady convection-diffusion-reaction problems in porous media},

author = {Loubna Salhi and Mohammed Seaid and Driss Yakoubi},

url = {https://www.sciencedirect.com/science/article/abs/pii/S0898122122003443},

year  = {2022},

date = {2022-08-01},

journal = {Computers & Mathematics With Applications},

volume = {124},

pages = {129-148},

abstract = {We study a class of steady nonlinear convection-diffusion-reaction problems in porous media. The governing equations consist of coupling the Darcy equations for the pressure and velocity fields to two equations for the heat and mass transfer. The viscosity and diffusion coefficients are assumed to be nonlinear depending on the temperature and concentration of the medium. Well-posedness of the coupled problem is analyzed and existence along with uniqueness of the weak solution is investigatedbased on a fixed-point method. An iterative scheme for solving the associated fixed-point problem is proposed and its convergence is studied. Numerical experiments are presented for two examples of coupled convection-diffusion-reaction problems. Applications to radiative heat transfer and propagation of thermal fronts in porous media are also included in this study. The obtained results show good numerical convergence and validate the established theoretical estimates.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{el-amrani_1887,

title = {An iterative scheme for solving acoupled Darcy-convection-diffusion model},

author = {Mofdi El-Amrani and Loubna Salhi and Mohammed Seaid and Driss Yakoubi},

url = {https://www.sciencedirect.com/science/article/pii/S0022247X22006175},

year  = {2022},

date = {2022-08-01},

journal = {Journal Of Mathematical Analysis And Applications},

volume = {517},

number = {2},

pages = {1-24},

abstract = {We present an iterative scheme for the numerical analysis of a class of coupled Darcy-convection-diffusion problems modelling flow and heat transfer in porous media. The governing equations consist of the Darcy equations for the flow coupled to a convection-diffusion equation for heat transfer with nonlinear viscosity and diffusion coefficient depending on the temperature. Existence and uniqueness of the weak solution for the considered problem are first analyzed using a fixed-point method and then convergence study of two iterative schemes for the fixed-point algorithm is presented. Two numerical examples are selected to validate the theoretical estimates and to demonstrate the performance of the proposed algorithm. The obtained results support our theoretical expectations for a good numerical convergence with the developed estimates.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{amirat_1963,

title = {Homogenization of MHD flows in porous media},

author = {Youcef Amirat and Kamel Hamdache and Vladimir V. Shelukhin},

url = {https://doi.org/10.1016/j.jde.2022.08.014},

year  = {2022},

date = {2022-08-01},

journal = {Journal Of Differential Equations},

volume = {339},

number = {339},

pages = {90-133},

abstract = {The paper is concerned with the homogenization of a nonlinear differential system describing the flow of an electrically conducting, incompressible and viscous Newtonian fluid through a periodic porous medium, in the presence of a magnetic field. We introduce a variational formulation of the differential system equipped with boundary conditions. We show the existence of a solution of the variational problem, and derive uniform estimates of the solutions depending on the characteristic parameters of the flow. Using the two-scale convergence method, we rigorously derive a two-scale equation for the two-scale current density, and a two-pressure Stokes system. We derive, in the case of constant magnetic permeability, an explicit relation expressing the macroscopic velocity as a function of the macroscopic Lorentz force, the pressure gradient, the external body force, and the macroscopic current density, via two permeability filtration ten- sors. When the magnetic field is absent, this relation reduces to the Darcy law.

© 2022 Elsevier Inc. All rights reserved.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{joseph_1864,

title = {Mechanical Properties and Damage Behavior of Polypropylene Composite (GF50-PP) Plate Fabricated by Thermocompression Process Under High Strain Rate Loading at Room and Cryogenic Temperatures},

author = {Fitoussi Joseph and Mohammad Hossein Nikooharf and Achraf Kallel and Mohammadali Shirinbayani},

url = {https://link.springer.com/article/10.1007/s10443-022-10047-y},

year  = {2022},

date = {2022-07-01},

journal = {Applied Composite Materials},

volume = {29},

number = {3},

pages = {1-21},

abstract = {This paper concerns the coupling effect of strain rate and temperature on the damage mechanical properties of the long-glass-fiber-reinforced polypropylene (GF50-PP) composite produced by the thermocompression process. Composite plates of GF50-PP have been employed to study the effect of glass fiber distribution on the mechanical properties of the composites. To achieve this objective the tensile tests have been performed at strain rate range from quasi-static to 100 s?1 at two loading temperatures of 20 °C and -70 °C, while measuring the local deformation through a contactless technique using a high-speed camera. High strain rate tensile tests findings showed that GF50-PP behavior is strongly strain-rate dependent. For instance, the stress damage threshold for three fiber orientations of 0°, 45°, and 90° to the Mold Flow Direction (MFD) was increased, when the strain rate varies from quasi-static (0.001 s?1) to 100 s?1 at two loading temperatures of 20 °C and -70 °C. The experimental methodology was coupled to microscopic observations using SEM to study the damage mechanisms of GF50-PP. The analysis confirms that there are three damage mechanisms: fiber-matrix interface debonding, matrix breakage, and pseudo-delamination between neighboring bundles of fibers.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}