IAO-Intel: An Ontology of Information Artifacts in the Intelligence Domain

We describe on-going work on IAO-Intel, an information artifact ontology developed as part of a suite of ontologies designed to support the needs of the US Army intelligence community within the framework of the Distributed Common Ground System (DCGS-A). IAO-Intel provides a controlled, structured vocabulary for the consistent formulation of metadata about documents, images, emails and other carriers of information. It will provide a resource for uniform explication of the terms used in multiple existing military dictionaries, thesauri and metadata registries, thereby enhancing the degree to which the content formulated with their aid will be available to computational reasoning

Modeling of a centrifuge device and validation of the efficiency estimate by comparison with experimental data

International audienceIn the nuclear industry and specifically in the context of nuclear spent fuel reprocessing, the function of a centrifuge is to stop the particles that were not dissolved by the nitric dissolution step. Those particles are not desirable in the liquid-liquid extraction devices responsible for recovering the noble materials. The high level of radioactivity of the involved materials usually makes impossible the basic measurements required for a better knowledge and optimization of the devices.In this context, the laboratory of chemical engineering and instrumentation of CEA Marcoule undertook a numerical modelling of centrifuges supported by experimental studies. Data acquisitions were performed on a CEPA LS laboratory scale centrifuge produced by the CEPA Company.Experimental studies gave access to the efficiency of the apparatus under operating conditions ranging from industrial conditions to so-called degraded conditions. Two types of powder were used for this study TiO$_2$ powders representative of the insoluble particles of the industrial process and a PMMA powder selected for its ease of measurement by standard laser granulometers.The numerical model, implemented in OpenFoam, handles three-phase-flows involving gas, water and particles. It is based on the combination of a Volume Of Fluid (VOF) solver with a lagrangian particle tracking solver using the Multi-Phase-Particle-In-Cell (MPPIC) method. The bowl rotation was modelled by the Multi-Reference-Frames2 (MRF) method.Comparison of the calculations with the experimental data validates the model for TiO$_2$ particle diameters greater than 0.5 $\mu$ for centrifugal accelerations ranging from 600 to 2000g and feed rates ranging from 21 to 42L/h. Below these sizes, the numerical model underestimates the efficiency of the laboratory centrifuge. Regarding the PMMA powder, the model showed the same trends as the experimental observations which indicated a poor efficiency of the centrifuge even at 2000g. The numerical model has been validated under operating conditions comparable to industrial conditions and can now be used as a tool to assist the industrial centrifuge management

Modeling of a centrifuge device and its validation by comparison with experimental data of the efficiency estimates

International audienceIn the nuclear industry and specifically in the context of nuclear spent fuel reprocessing, the function of a centrifuge is to stop the particles that were not dissolved by the nitric dissolution step. Those particles are not desirable in the liquid-liquid extraction devices responsible for recovering the noble materials. The high level of radioactivity of the involved materials usually makes impossible the basic measurements required for a better knowledge and optimization of the devices.In this context, the laboratory of chemical engineering and instrumentation of CEA Marcoule undertook a numerical modelling of centrifuges supported by experimental studies. Data acquisitions were performed on a CEPA LS laboratory scale centrifuge produced by the CEPA Company.Experimental studies gave access to the efficiency of the apparatus under operating conditions ranging from industrial conditions to so-called degraded conditions. Two types of powder were used for this study TiO2 powders representative of the insoluble particles of the industrial process and a PMMA powder selected for its ease of measurement by standard laser granulometers.The numerical model, implemented in OpenFoam, handles three-phase-flows involving gas, water and particles. It is based on the combination of a Volume Of Fluid3 (VOF) solver with a lagrangian particle tracking solver using the Multi-Phase-Particle-In-Cell1 (MPPIC) method. The bowl rotation was modelled by the Multi-Reference-Frames2 (MRF) method.Comparison of the calculations with the experimental data validates the model for TiO2 particle diameters greater than 0.5 and#956;m for centrifugal accelerations ranging from 600 to 2000g and feed rates ranging from 21 to 42L/h. Below these sizes, the numerical model underestimates the efficiency of the laboratory centrifuge. Regarding the PMMA powder, the model showed the same trends as the experimental observations which indicated a poor efficiency of the centrifuge even at 2000g.The numerical model has been validated under operating conditions comparable to industrial conditions and can now be used as a tool to assist the industrial centrifuge management

Similar scaling of contralateral and ipsilateral cortical responses during graded unimanual force generation

Hemibody movements are strongly considered as being under the control of the contralateral hemisphere of the cerebral cortex. However, some neuroimaging studies have found a bilateral activation of either the pri- mary sensori-motor (SM1) areas or the rostral prefrontal cortex (PFC), during unimanual tasks. More than just bilateral, the activation of these areas was found to be symmetrical in some studies. However, the sym- metrical response remains strongly controversial notably for handgrip force generations. We therefore aimed to examine the bilateral SM1 and rostral PFC area activations in response to graded submaximal force gener- ation during a unilateral handgrip task. Fifteen healthy subjects performed 6 levels of force (ranging from 5 to 50% of MVC) during a handgrip task. We concomitantly measured the activation of bilateral SM1 and rostral PFC areas through near-infrared spectroscopy (NIRS) and the electromyographic (EMG) activity of the bilat- eral fl exor digitorum super fi cialis (FDS) muscles. Symmetrical activation was found over the SM1 areas for all the investigated levels of force. At the highest level of force (i.e., 50% of MVC), the EMG of the passive FDS increased signi fi cantly and the ipsilateral rostral PFC activation was found more intense than the correspond- ing contralateral rostral PFC activation. We suggest that the visuo-guided control of force levels during a handgrip task requires the cross-talk from ipsi- to contralateral SM1 to cope for the relative complexity of the task, similar to that which occurs during complex sequential fi nger movement. We also propose alterna- tive explanations for the observed symmetrical SM1 activation including (i) the ipsilateral corticospinal tract and (ii) interhemispheric inhibition (IHI) mechanism. The increase in EMG activity over the passive FDS could be associated with a release of IHI at 50% of MVC. Finally, our results suggest that the greater ipsilateral (right) rostral PFC activation may re fl ect the greater demand of attention required to control the motor out- put at high levels of forc

Influence of particle size and shape properties on cake resistance and compressibility during pressure filtration

International audienceThe aim of this paper was to study cake filterability and compressibility as a function of the particle shape and particle size distribution (PSD). Different shapes and PSD of calcium carbonate and uranium oxalate particles covering the classical types encountered in industry (sphere, cube, needle and platelet) were obtained by precipitation. The size and shape factor distributions were measured using an image analysis system on SEM pictures. The cake filtration properties were measured in ideal monitored operating conditions, because of a miniaturised filtration cell set-up. The impact of the PSD and the shape were quantitatively assessed. These two solid features have an impact on cake resistance and compressibility, but not in the same way. The PSD has the strongest effect on cake resistance and compressibility. The particle shape is a decisive parameter for cake compressibility when the shape is far from the sphere. Both parameters need to be considered when working on the development of a filtration operation. Here, a practical model built following the Darcy law coupled with a new correlation for compressibility factor assessment is proposed. It gave satisfactory estimates of cake filterability and compressibility for the four shapes studied

Performance and brain activity during a spatial working memory task: application to pilot candidate selection

International audienceFor 18 ab initio airline pilots, we assessed the possibility of predicting flight simulator performance with the performance and the prefrontal activity measured during a spatial working memory (SWM) task. Behavioral results revealed that a better control of the aircraft altitude in the flight simulator was correlated with better strategy during the SWM task. In addition, neuroimaging results suggested that participants that recruited more neural resources during the SWM task were more likely to accurately control their aircraft. Taken together, our results emphasized that spatial working memory and the underlying neural circuitries are important for piloting. Ultimately, SWM tasks may be included in pilot selection tests as it seems to be a good predictor of flight performance