Le pseudo-féminisme du néo-conservatisme féminin

Le féminisme a réussi à transformer partiellement le monde dans lequel nous vivons. Mais la résistance de la société traditionnelle à ces changements, ainsi que la remontée de la droite et la valorisation forcenée de l'individualisme, risquent de compromettre ses acquis. Dans ce contexte, l'avènement d'un discours pseudo-féministe qui véhicule les valeurs traditionnellement considérées comme « féminines » par les hommes risque d'embrouiller le message féministe pour tous ceux qui y accordaient créance et espéraient le voir aller plus loin dans sa quête d'une société nouvelle. Nous voulons analyser ce discours en montrant comment il tend à remettre en question l'effort de transformation sociale amorcé par le féminisme.Feminism has partly transformed our world. Traditionnal society's resistance to these changes together with the rise of the Right and individualism endanger these gains. In that context, the advent of pseudo-feminist discourse carrying the values traditionnally seen by men as "féminine" might blur the feminist message for those who give it credit and hope to see it progress in its quest for a new society. We wish to analyse that discourse and show how it tends to challenge the social transformation effort launched through feminism

Modeling of ash deposition on the wall of a high temperature thermal reformer

Gasification of biomass is a suitable approach allowing the conversion of non-homogeneous biomass into a homogeneous intermediary, syngas. High thermal conversion of char and tar intermediates can only be achieved at high temperatures (\u3e 1300oC) without the addition of a catalytic system. Such an approach however can induce melting of inert ashes coming with the feedstock, which can stick to the reactor wall, thus possibly leading to agglomeration/clogging problems, as well as leaching of the refractory if not properly controlled. One possible way to address ash deposition is to use a cooling system at the reactor walls. The deposited slag layer acts as refractory itself, so that the inner temperature becomes high enough to exceed the ash solidification temperature. The new deposited ashes then flow down along the walls in liquid phase, and can be collected and disposed. A transient 2D model was developed and implemented to describe the evolution of the slag layer on a reformer walls. The effect of operating variables on the layer thickness was studied through sensitivity analysis. The model equations were also used to devise a set of dimensionless numbers that can fully characterize the slag behaviour in the system. These numbers were used to downscale the thermal reformer into a cold transparent bench. The latter will be used for model calibration and validation regarding slag fluid dynamic behavior

Numerical and experimental study of a multiphase cold bubbling bed reactor

A lab scale bubbling fluidized bed reactor was simulated using a CFD model, aiming at investigating and ultimately matching its overall fluid dynamic behaviour and mostly the bubbles “footprints” on the pressure drop signal. In order to validate the model, a cylindrical transparent reactor (PVC) has been assembled. This system, operating at ambient condition, was filled with aluminum oxide (Geldart group B particles) and homogeneously fluidized using compressed air flowing through a porous plate. A high frequency differential pressure gauge was used to measure the pressure drop across the bed. In addition, videos were recorded using a commercial camera and the generated dynamic slow motions frames combined with the still frames analysis contributed to the investigation of this system. Using Fluent-Ansys software, a 2D-Cartesian Two Fluid Model (TFM) was implemented, numerically verified and validated against experimental data using a Power Spectral Density (PSD) analysis of the pressure drop signal. Empirical data also suggested a minimum data capture time for pressure drop records and results showed that a 40 seconds sampling time was could be considered as a minimum threshold to capture a representative PSD distribution of the pressure oscillations. Based upon this finding, several simulations were performed to investigate the model sensitivity to the variation of some parameters specific to granular flows. Specifically, the 2D TFM sensitivity was tested by varying the formulation for the solid pressure terms, the values of the experimental minimum fluidization velocity (used as a calibration point for the parametric drag law used in this study), and restitution coefficients for particles collisions. Related results have been plotted against each other along with the experimental ones and afterwards analyzed. Comparison with the experimental data of the 2D-TFM model has proved to be satisfactory in matching the time-averaged pressure drop, the pseudo stationary bed expansion, its bubbles shape and ultimately capturing the total pressure drop “power”, evaluated as the integral of its Power Spectral Density (PSD). The 2D model showed limitations in reproducing correctly the experimental PSD in the 0-10 Hz range, where the effect of bubbles are more significant. To overcome this limit, a 3-D version of this TFM model was implemented and tested. The analysis of the pressure drop spectrum showed how the 3D TFM model could overcome the aforementioned limitation of the corresponding 2D version. However, the quite coarse mesh size used to reduce the computational time did not allowed capturing the total power of the pressure drop oscillation. Our current efforts address the implementation and validation of a 3D-Dense Discrete Particle Model (DDPM) linked to this lab scale system such as to evaluate the performance and accuracy of this new approach with regards to the TFM previously tested. Such an approach would also contribute to reduce computational costs, this introducing the parcels concept. Collisions between these parcels is accounted throughout the soft-sphere (DEM) model where a linear spring-dashpot model is used. The effect of parcels number as well as DEM parameters variation on the pressure drop has also been investigated and analyzed