University of Technology of Compiègne, France
University of Technology of Compiègne, France

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Daoussi R.,University Claude Bernard Lyon 1 | Daoussi R.,University Technologique Of Compiegne | Bogdani E.,University Claude Bernard Lyon 1 | Vessot S.,University Claude Bernard Lyon 1 | And 2 more authors.
Drying Technology | Year: 2011

We have investigated principally the influence of organic solvent concentration of the formulation corresponding to water {thorn}tert-butanol (TBA) mixtures and of the freezing rates on solvent crystals morphology on some thermodynamical properties (vapor pressures and sublimation enthalpies) and on sublimation kinetics. The solvent crystals' morphology of frozen formulations showed unexpected behavior compared with the previous literature data reported for water-based formulations. Indeed, the super cooling degrees decreased by increasing the freezing rates and, consequently, the mean sizes of solvent crystals increased with the freezing rates. Otherwise, at the eutectic composition, namely at 90% (w/w) of TBA, we observed that the equilibrium vapor pressure data for solid-vapor system (sublimation) were twice higher than the data obtained with pure water systems. Moreover, the sublimation enthalpy values of organic formulations were only a quarter to a third of that of pure water. These specific thermodynamical data explained principally the faster sublimation kinetics observed during freeze-drying of our active principle ingredient (API) with TBA co-solvent formulations. © 2011 Taylor & Francis Group, LLC.


Yan L.,University of Savoy | Badel A.,University of Savoy | Petit L.,University Technologique Of Compiegne | Formosa F.,University of Savoy
Journal of Physics: Conference Series | Year: 2015

This paper reports the practical design and experimental testing of a piezoelectric energy reclamation system. The presented system aims at scavenging energy from a miniaturized electromagnetic digital actuator for additional function such as obtains the discrete position information for enhanced reliability. Based on frequency up conversion technique, and the considered actuator dynamical responses, a piezoelectric energy harvester has been experimentally evaluated. In plane integration is the next step. © Published under licence by IOP Publishing Ltd.


Fontaine E.,French Institute of Petroleum | Orsero P.,University Technologique Of Compiegne | Ledoux A.,ZI Athelia I Voie Ariane | Nerzic R.,Actimar | And 2 more authors.
Structural Safety | Year: 2013

The present study is an attempt to re-assess the level of reliability of the mooring system of an existing Floating Production Storage and Offloading (FPSO) unit in West Africa. The study made use of field data for the environment including wind, waves and current together with simultaneous measurements of the FPSO offset and of the mooring line tensions. Three different approaches to predict the extreme response are compared. More specifically, the traditional design method is compared with Response Based Design (RBD) and First Order Reliability Method (FORM) analysis associated with Response Surface Models (RSM) of the moored FPSO. The results of this case study allow assessing the level of conservatism that is currently embedded in classical design rules. © 2013 Elsevier Ltd.


Fakeri-Tabrizi A.,University Pierre and Marie Curie | Amini M.-R.,Joseph Fourier University | Goutte C.,National Research Council Canada | Usunier N.,University Technologique Of Compiegne
Neurocomputing | Year: 2015

In many applications, observations are available with different views. This is, for example, the case with image-text classification, multilingual document classification or document classification on the web. In addition, unlabeled multiview examples can be easily acquired, but assigning labels to these examples is usually a time consuming task. We describe a multiview self-learning strategy which trains different voting classifiers on different views. The margin distributions over the unlabeled training data, obtained with each view-specific classifier are then used to estimate an upper-bound on their transductive Bayes error. Minimizing this upper-bound provides an automatic margin-threshold which is used to assign pseudo-labels to unlabeled examples. Final class labels are then assigned to these examples, by taking a vote on the pool of the previous pseudo-labels. New view-specific classifiers are then trained using the labeled and pseudo-labeled training data. We consider applications to image-text classification and to multilingual document classification. We present experimental results on the NUS-WIDE collection and on Reuters RCV1-RCV2 which show that despite its simplicity, our approach is competitive with other state-of-the-art techniques. © 2014 Elsevier B.V.


Jackowiak D.,Polytechnic Institute of LaSalle Beauvais | Jackowiak D.,University Technologique Of Compiegne | Frigon J.C.,National Research Council Canada | Ribeiro T.,Polytechnic Institute of LaSalle Beauvais | And 2 more authors.
Bioresource Technology | Year: 2011

This study investigated the effects of microwave pretreatment of switchgrass in order to enhance its anaerobic digestibility. Response surface analysis was applied to screen the effects of temperature and time of microwave pretreatment on matter solubilisation. The composite design showed that only temperature had a significant effect on solubilisation level. Then the effects of the microwave pretreatment were correlated to the pretreatment temperature. The sCOD/tCOD ratio was equal to 9.4% at 90°C and increased until 13.8% at 180°C. The BMP assays of 42days showed that microwave pretreatment induced no change on the ultimate volume of methane but had an interesting effect on the reaction kinetic. Indeed, the time required to reach 80% of ultimate volume CH4 is reduced by 4.5days at 150°C using the microwave pretreatment. © 2010 Elsevier Ltd.


Jackowiak D.,Polytechnic Institute of LaSalle Beauvais | Jackowiak D.,University Technologique Of Compiegne | Bassard D.,Polytechnic Institute of LaSalle Beauvais | Bassard D.,University Technologique Of Compiegne | And 2 more authors.
Bioresource Technology | Year: 2011

This study aims at the optimisation of a microwave pretreatment for wheat straw solubilisation and anaerobic biodegradability. The maximum yield of methane production was obtained at 150°C with an improvement of 28% compared to an untreated sample. In addition, at this temperature, the time to reach 80% of the methane volume obtained from untreated straw was about 35%. The study of ramp time and holding time at targeted temperature showed that they had no improvement effect. Thus, the best conditions are the highest heating rate for a final temperature 150°C without any holding time. The reading of energy consumed by pretreatment and energy overproduced by pretreated samples showed that increasing tVS amount and heating rate led to a saving of energy consumption. Nevertheless, to obtain a positive energy balance, a microwave device should consume less than 2.65kJ/gtVS. © 2011 Elsevier Ltd.


PubMed | AMS Envolure, SIAAP and University Technologique Of Compiegne
Type: | Journal: Bioresource technology | Year: 2016

This short communication briefly presents a rapid method using a fluorescent redox indicator, similar to resazurin, in order to estimate the biodegradability of sewage sludge during anaerobic digestion (AD). The biodegradability and by extension the Biochemical Methane Potential (BMP) of nineteen municipal sludge samples (primary, biological and tertiary) were investigated and estimated in only 48 h. Results showed the relevance to follow the metabolic activity of anaerobic sludge by the kinetic of probe reduction. The extended lag phase of inoculum indicated an impact of pre-treatments on enzyme activity. The comparison with Automatic Methane Potential Test System II (AMPTS) confirmed the estimated values of BMP according to an uncertainty limit of 25%. These first results highlight the interest of this rapid assay as a preliminary tool of the biodegradability of sewage sludge in anaerobic digestion.


Olivier J.,Laboratoire Of Thermique Energetique Et Procedes | Mahmoud A.,Laboratoire Of Thermique Energetique Et Procedes | Vaxelaire J.,Laboratoire Of Thermique Energetique Et Procedes | Conrardy J.-B.,Laboratoire Of Thermique Energetique Et Procedes | And 2 more authors.
Drying Technology | Year: 2014

Electro-dewatering experiments were carried out on a laboratory-scale device to analyze the energy consumption under both a constant voltage (C.V.) and a constant current density (C.C.). The purpose of this study was to determine the impact of electro-dewatering parameters (voltage, current density, pressure, and amount of sludge to be treated) on energy consumption. The results of the C.V. experiments showed a very strong correlation between the applied voltage, the final dryness of the sludge filter-cake, and the total energy consumption (Wh/kgadditional water removed). The calculation of the instantaneous energy consumption allowed us to determine the range of dryness where the electro-dewatering process (EDW) was energetically more advantageous than thermal drying. The instantaneous energy consumption depends mainly on the reached dryness. It does not significantly depend on other process parameters such as the applied voltage, the applied current density (in), the applied pressure, or the initial amount of sludge. In fact, the change in electrical power consumption due to different test conditions was balanced by changes in kinetics. The comparison between two tests (one with C.V. conditions, the other with C.C. conditions) showed that the kinetics were similar when the electrical power consumption was the same. The results of this work lead to two main findings: the dewatering kinetics depends essentially on the current density; and the final dryness of the filter-cake depends mainly on the applied voltage. © 2014 Copyright Taylor & Francis Group, LLC.


Bennouna S.,Valeo Thermique Habitacle | Moreau S.,University Technologique Of Compiegne | Ville J.M.,University Technologique Of Compiegne | Cheriaux O.,Valeo Thermique Habitacle
SAE Technical Papers | Year: 2016

The noise radiated inside the car cabin depends on many sources such as the embedded equipments like the Heating, Ventilation and Air Conditioning (HVAC) module. An HVAC is a compact and complex system composed of several elements: blower, flaps, thermal exchangers, ducts. Air provided by an HVAC is blown by a blower passing through different components and then distributed to car cabin areas. Interactions between airflow and the HVAC fixed components generate noises that emerge in the car cabin. CEVAS project, managed by the automotive equipment manufacturer Valeo, is aiming to develop a prediction tool which will provide HVAC noise spectrum and sound quality data. The tool is based, in particular, on aeroacoustic characterization of individual elements and associations of elements. An experimental test bench was therefore developed by the acoustic laboratory of the University of Technology of Compiègne (UTC) based on the assumption that an HVAC component is described as a 2N-port source (N cut-on modes) represented by its scattering matrix and its upstream and downstream modal acoustic pressure vectors. In addition measurements of mean flow velocities around the elements are performed by Particle Image Velocimetry (PIV) equipment. In this paper, results of the fluid and aeroacoustic qualification of a flap for different opening angles without and with a wall located upstream the flap are presented. Analysis is conducted based on the noise prediction model for aerodynamic sound production in low speed flow ducts suggested by Nelson and Morfey in 1981. Copyright © 2016 SAE International.


Lartizien C.,CNRS Research Center for Image Acquisition and Processing for Health | Aubin J.-B.,University Technologique Of Compiegne | Buvat I.,University Paris Diderot
IEEE Transactions on Medical Imaging | Year: 2010

Two groups of bootstrap methods have been proposed to estimate the statistical properties of positron emission tomography (PET) images by generating multiple statistically equivalent data sets from few data samples. The first group generates resampled data based on a parametric approach assuming that data from which resampling is performed follows a Poisson distribution while the second group consists of nonparametric approaches. These methods either require a unique original sample or a series of statistically equivalent data that can be list-mode files or sinograms. Previous reports regarding these bootstrap approaches suggest different results. This work compares the accuracy of three of these bootstrap methods for 3-D PET imaging based on simulated data. Two methods are based on a unique file, namely a list-mode based nonparametric (LMNP) method and a sinogram based parametric (SP) method. The third method is a sinogram-based nonparametric (SNP) method. Another original method (extended LMNP) was also investigated, which is an extension of the LMNP methods based on deriving a resampled list-mode file by drawings events from multiple original list-mode files. Our comparison is based on the analysis of the statistical moments estimated on the repeated and resampled data. This includes the probability density function and the moments of order 1 and 2. Results show that the two methods based on multiple original data (SNP and extended LMNP) are the only methods that correctly estimate the statistical parameters. Performances of the LMNP and SP methods are variable. Simulated data used in this study were characterized by a high noise level. Differences among the tested strategies might be reduced with clinical data sets with lower noise. © 2006 IEEE.

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