Soogund D.,French Institute of Petroleum |
Lecour P.,French Institute of Petroleum |
Daudin A.,French Institute of Petroleum |
Guichard B.,French Institute of Petroleum |
And 3 more authors.
Applied Catalysis B: Environmental | Year: 2010
In order to understand the role of vanadium and its interaction with molybdenum atoms in the catalysts used for the hydrotreatment of residues, mixed heteropolyanion (HPA) precursors PMo(12-x)VxO40 (3+x)- have been prepared and deposited by incipient wetness impregnation on an alumina support. The evolution of the compounds in the impregnating solutions till their deposition on the support has been analysed using various spectroscopic techniques such as Raman, 31P and 51V NMR, XPS as well as TEM. Activity measurements on model molecules (toluene and cyclohexane) and on real feedstock (vacuum residue) have been performed after activation step (ex situ sulphidation). Hydrogenation (HYD), isomerisation (ISOM), hydrodemetallation (HDM), hydrodesulphurisation (HDS), hydrodeasphaltenisation (HDAsC7) were assessed. During tests (2 h) on a Safaniya vacuum residue feed, interesting HDM activity was observed compared to reference promoted and unpromoted catalysts (NiMo and Mo/Al2O3). It can be concluded that the use of vanadium in the impregnating solution may promote HDM and HDAsC7 (increase of vanadium removal rate around 15% compared to Mo-catalyst without vanadium). Furthermore HDM and HDAsC7 catalytic performances turned out to be close to the ones of NiMo catalyst. The increase in HDM/HDAsC7 activity may be related to the improvement of hydrogenation and/or isomerisation, the latter being improved by the presence of vanadium. © 2010 Elsevier B.V. All rights reserved.
Zhang S.,East China Normal University |
Zhang S.,Shanghai Normal University |
Liu Q.,East China Normal University |
Shen M.,East China Normal University |
And 4 more authors.
Dalton Transactions | Year: 2012
To overcome the separation difficulty of the palladium-based homogeneous catalyst, the palladium complex can be anchored on various supports such as silica, polymers and nanoparticles. For the same purpose, we describe a general and facile method to immobilize palladium bis(phosphine) complexes on the basis of the technique widely used for metal-organic framework (MOF) synthesis, yielding a mesoporous coordination polymer palladium-CP1. Although palladium complexes are generally not stable enough to allow further manipulation, we succeeded in preparation of a palladium coordination polymer without by-product Pd clusters or nanoparticles. The fresh palladium-CP1 catalyst exhibits a yield close to 55% for tolane at room temperature and 24 h in Sonogashira coupling of iodobenzene and phenylacetylene, as compared with a yield of 89% for its homogeneous counterpart [Pd(PPh 3) 2Cl 2]. Furthermore, this catalyst is stable enough to be reused more than four times with no Pd and Zn leaching. Therefore this new immobilization method offers great promise for the produce of recyclable palladium heterogeneous catalysts with higher activity and higher thermal and chemical stability in the future. © 2012 The Royal Society of Chemistry.
Stoclet G.,University Of Lille1 |
Seguela R.,University Of Lille1 |
Seguela R.,INSA Lyon |
Vanmansart C.,University Of Lille1 |
And 2 more authors.
Polymer | Year: 2012
This work deals with the in situ and ex situ WAXS study of the strain-induced structural changes in relation to the mechanical behavior of a semi-crystalline polylactide containing 4% of d-stereomer units. The crystals isothermally generated at 120 °C were in the α form. The draw temperature was in the range 65 °C < T d < 90 °C, i.e. just above T g. In this T d range isothermal crystallization was so slow that only strain-induced crystals could be generated during the time scale of the experiments. This allowed studying samples with various initial levels of crystallinity, X cr. For X cr = 5%, the early occurrence of strain-hardening contrasted with the case of the amorphous material. This was due to the physical crosslinking of the macromolecular network by the crystallites that prevented chain relaxation since the onset of drawing. Strain-induced α′ crystals developed in parallel with the mesophase, the respective amount of the two phases being dependent on T d. For X cr = 24%, the drawing behavior was that of a crosslinked and filled elastomer. Again, both strain-induced α′ crystals and mesophase occurred in various proportions in relation to T d. For X cr = 40%, it was shown that the initial α crystals underwent partial destruction and subsequent reorganization into mesophase and/or α′ crystals. Whatever T d and X cr, the total amount of ordered phases, i.e. crystal + mesophase, did not exceed the value of 40% that was the maximum accessible crystal content for the present material. A mechanism of plastic deformation involving twinning is proposed from the WAXS analysis of the crystalline texturing in the case X cr = 40%. AFM observations as a function of strain corroborate the proposed deformation scheme. © 2011 Elsevier Ltd. All rights reserved.
Marcon L.,French National Center for Scientific Research |
Riquet F.,University of Lille1 |
Vicogne D.,French National Center for Scientific Research |
Szunerits S.,French National Center for Scientific Research |
And 2 more authors.
Journal of Materials Chemistry | Year: 2010
Recently, nanodiamond particles (ND) have emerged as a promising tool in the field of nanobiotechnology. However, studies about the impact of ND on living organisms are still limited to raw materials and primarily confined to in vitro studies. In this work, we investigated the cytotoxicity and in vivo toxicity of ND correlated with their chemical surface functionality (-OH, -NH2 or -CO2H). Two model systems have been used, human embryonic kidney 293 (HEK293) cells and Xenopus laevis embryos. Cell viability assays showed that ND were not cytotoxic to HEK293 cells for concentrations below 50 μg mL-1. Our data suggest that the cytotoxicity may be due to the affinity of cationic particles for the negatively charged cell membrane. In parallel, visual monitoring of microinjected early-stage embryos showed a potential embryotoxicity and teratogenicity for carboxylated ND-CO 2H. ND seem to have a negative impact on the gastrulation and neurulation stages inducing phenotypical abnormalities and high mortality. © 2010 The Royal Society of Chemistry.
Bakli H.,University of Lille1 |
Haddadi K.,University of Lille1 |
Lasri T.,Lille University of Science and Technology
Conference Record - IEEE Instrumentation and Measurement Technology Conference | Year: 2013
An interferometric technique for scanning near-field microscopy applications is proposed. The method is based on the association of a vector network analyzer, an evanescent microwave coaxial probe and a precise interferometer built up with a power divider, a phase-shifter and an attenuator. Advantages such as simplicity of operation, broad frequency band capabilities and high measurement sensitivity are achieved. In particular, a scanning near-field microwave microscope is built and experiments related to the measurement sensitivity in the frequency range 2-6 GHz are demonstrated. © 2013 IEEE.
Derimian Y.,University Of Lille1 |
Dubovik O.,University Of Lille1 |
Tanre D.,University Of Lille1 |
Goloub P.,University Of Lille1 |
And 2 more authors.
Journal of Geophysical Research: Atmospheres | Year: 2012
In this work we characterize optical properties and assess the direct radiative effect of an ash plume observed on April 17, 2010 by AERONET, lidar and broadband solar flux measurements collocated on the roof of the Laboratory of Atmospheric Optics in Lille, northern France. These measurements allowed experimental evaluation of ash radiative impact and validation of simulations. The derived aerosol model of ash is characterized by a bi-modal size distribution dominated by coarse mode centered at a radius of 1.5 μm and by relatively strong absorption at short wavelengths (single scattering albedo of 0.81 ± 0.02 at 440 nm as opposed to 0.92 ± 0.02 at 670, 870 and 1020 nm). Due to relatively low aerosol optical thickness during the ash plume transport (∼0.26 at 440 nm), which is unfavorable for AERONET retrievals, the uncertainties in derived ash aerosol model were additionally evaluated. The complex refractive index of ash was derived assuming that effective refractive index retrieved by AERONET for externally mixed bi-component aerosol can be approximated as an average of refractive indices of two components weighted by their volume concentrations. Evaluation of the accuracy of this approximation showed acceptably small errors in simulations of single scattering albedo and aerosol phase function over the range of scattering angles observed by the AERONET almucantar. Daily average radiative forcing efficiency of ash calculated for a land surface reflectance representing Lille was about -93 ± 12 Wm-2 τ550 -1 and -31 ± 2 Wm -2 τ550 -1 at the bottom and top of the atmosphere; the values for an ocean surface reflectance are also provided. Copyright 2012 by the American Geophysical Union.
Touati Y.,University of Lille1
2011 IEEE International Conference on Robotics and Biomimetics, ROBIO 2011 | Year: 2011
This paper deals with robust fault detection and isolation using bond graph approach and linear filters. The bond graph tool is used to model the dynamic system and the uncertainties on the sensors and actuators. The same model is used to generate systematically the analytical redundancy relations and the thresholds. A specific form of digital linear filter is used to evaluate the residuals and to ameliorate the robustness and the detectability of the faults. the developed procedure is applied to experimental data of an electromechanical system which is a subsystem of a mobile robot named Robotino. © 2011 IEEE.
Rouillard J.,University of Lille1 |
Tarby J.-C.,University of Lille1
International Journal of Ad Hoc and Ubiquitous Computing | Year: 2011
We are involved in conceiving and implementing man-machine interfaces allowing multimodal and situated dialogue in order to interact with smart digital environments. Several methods are presented depending on how and what the user can say. We describe our approach and some tracks to permit to end-users to communicate more naturally with their house, by speech or by gesture, for instance. Some applications based on workflow description are presented to show how designers are able to model their own man-machine dialogue. Finally, this work is complemented with a Model Driven Engineering approach using Statecharts for a smart digital home. Copyright © 2011 Inderscience Enterprises Ltd.
De-La-Ossa-Carretero J.A.,University of Alicante |
Dauvin J.-C.,University Of Lille1 |
Dauvin J.-C.,University of Caen Lower Normandy
Transitional Waters Bulletin | Year: 2010
1 - The assessment of quality status of Transitional Aquatic Ecosystems remains a challenge for the ecologists. 2 - Here, we compared the results of two common indices (AMBI - Ecological Groups and BOPA/BO2A-Taxonomic Sufficiency) from samples coming from the north-eastern Atlantic and Mediterranean Sea. Both biotic indices rely on distinct assessments of species sensitivity/tolerance. 3 - Six studies provided the raw data that permitted AMBI and BOPA to be compared. A total 922 data element was available, most of them from the Seine estuary (78%). The database was later divided into three sub-sets: French Atlantic Transitional Waters, Mediterranean Coastal Waters and Mediterranean Lagoons. 4 - Both indices' values demonstrated a strong correlation; however, the BOPA index had a tendency to overestimate the EcoQS compared to the values obtained from AMBI index, mainly due to discrepancies between 'high' and 'good' quality. 5 - New thresholds for BOPA/BO2A index are proposed in order to reduce this overestimation. © 2008 University of Salento - SIBA.
d'Haese R.,Ecole Nationale Supérieure de Chimie de Lille |
Pawlowski L.,Ecole Nationale Supérieure de Chimie de Lille |
Bigan M.,Probiogem |
Jaworski R.,Ecole Nationale Supérieure de Chimie de Lille |
Martel M.,University of Lille1
Surface and Coatings Technology | Year: 2010
Fine, hydroxyapatite (HA) powder, synthesized using calcium nitrate and diammonium nitrate was formulated with water and alcohol to obtain a suspension used to plasma spray coatings onto titanium substrates. The deposition process was optimized using statistical design of 2n experiments with two variables: spray distance and electric power input to arc plasma. The sprayed coatings were soaked in simulated body fluid (SBF) for the periods of 3, 7, 14, 28, and 60 days at controlled temperature of 37 °C. The reference intensity ratio (RIR) method basing onto X-ray diffraction (XRD) data was used to determine quantitatively the phase composition of as-sprayed and soaked deposits. Electron probe microanalysis (EPMA) enabled to make the profiles of calcium to phosphorus atomic ratio along a line though the coatings' cross sections. Raman spectroscopy of selected samples enabled to localize the different crystal phases in sprayed coatings. The coatings included some porosity and have two characteristic zones: (i) dense zone corresponding to the lamellas, observed usually in thermally sprayed coatings; (ii) sintered zone containing fine hydroxyapatite grains which correspond to the fine solids from the suspension which were agglomerated in the cold regions of plasma jet and sintered on the substrate. The soaking in SBF homogenizes the morphology of coatings. The sintered zone disappears and the pores get filled by the reprecipitated calcium phosphates. © 2009 Elsevier B.V. All rights reserved.